2019-01-17 02:48:29

by Ran Wang

[permalink] [raw]
Subject: [PATCH 0/2] usb: dwc3: Add avoiding vbus glitch happen during xhci reset

This to fix USB enumeration compatibility issue found on DWC3 (host mode)
IP only.

Some pre-discussion mails can be referred from:
https://lkml.org/lkml/2018/11/23/387
https://lkml.org/lkml/2018/11/22/683

As to the workaround, I know programming xhci register in DWC3 dirver
(probe function) is not good from perspective of SW stack, but it seems
to be the only place to fix this real existing problem (test result show
that doing this in xhci-plat.c or xhci.c would not hlep on this kind of
failure). If who have better idea, please let me know, thanks in advanced.

Ran Wang (2):
dt-bindings: Add workaround for host mode VBUS glitch when boot
dwc3 core driver: Add avoiding vbus glitch happen during xhci reset

Documentation/devicetree/bindings/usb/dwc3.txt | 3 +++
drivers/usb/dwc3/core.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
drivers/usb/dwc3/core.h | 10 +++++++++-
3 files changed, 60 insertions(+), 0 deletions(-)
--
1.7.1



2019-01-16 18:26:45

by Ran Wang

[permalink] [raw]
Subject: [PATCH 1/2] usb: dwc3: Add avoiding vbus glitch happen during xhci reset

When DWC3 is set to host mode by programming register DWC3_GCTL, VUBS
(or its control signal) will on immediately on related Root Hub ports.
Then the VUBS will be de-asserted for a little while during xhci
reset (conducted by xhci driver) for a little while and back to normal.

This VBUS glitch might cause some USB devices emuration fail if kernel boot
with them connected. One SW workaround which can fix this is to program
all PORTSC[PP] to 0 to turn off VBUS immediately after setting host mode
in DWC3 driver(per signal measurement result, it will be too late to do
it in xhci-plat.c or xhci.c).

Signed-off-by: Ran Wang <[email protected]>
---
Documentation/devicetree/bindings/usb/dwc3.txt | 3 +++
1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt
index 8e5265e..dadb530 100644
--- a/Documentation/devicetree/bindings/usb/dwc3.txt
+++ b/Documentation/devicetree/bindings/usb/dwc3.txt
@@ -106,6 +106,9 @@ Optional properties:
When just one value, which means INCRX burst mode enabled. When
more than one value, which means undefined length INCR burst type
enabled. The values can be 1, 4, 8, 16, 32, 64, 128 and 256.
+ - snps,avoid-vbus-glitch-when-set-host: Power off all Root Hub ports immediately
+ after setting host mode to avoid vbus (negative) glitch happen in later
+ xhci reset. And the vbus will back to 5V automatically when reset done.

- in addition all properties from usb-xhci.txt from the current directory are
supported as well
--
1.7.1


2019-01-16 18:27:42

by Ran Wang

[permalink] [raw]
Subject: RE: [PATCH 1/2] usb: dwc3: Add avoiding vbus glitch happen during xhci reset

Hi,

On 16, 2019 14:48 Ran Wang wrote:
>

It seems the preface patch (0/2) failed to be accepted by patchwork (could
anyone tell me how to generate it properly with some sommand?),
I paste its content here for your reference :

This to fix USB enumeration compatibility issue found on DWC3 (host mode)
IP only.

Some pre-discussion mails can be referred from:
https://lkml.org/lkml/2018/11/23/387
https://lkml.org/lkml/2018/11/22/683

As to the workaround, I know programming xhci register in DWC3 dirver
(probe function) is not good from perspective of SW stack, but it seems
to be the only place to fix this real existing problem (test result show
that doing this in xhci-plat.c or xhci.c would not hlep on this kind of
failure). If who have better idea, please let me know, thanks in advanced.

Ran Wang (2):
dt-bindings: Add workaround for host mode VBUS glitch when boot
dwc3 core driver: Add avoiding vbus glitch happen during xhci reset

Documentation/devicetree/bindings/usb/dwc3.txt | 3 +++
drivers/usb/dwc3/core.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
drivers/usb/dwc3/core.h | 10 +++++++++-
3 files changed, 60 insertions(+), 0 deletions(-)

> When DWC3 is set to host mode by programming register DWC3_GCTL, VUBS
> (or its control signal) will on immediately on related Root Hub ports.
> Then the VUBS will be de-asserted for a little while during xhci reset
> (conducted by xhci driver) for a little while and back to normal.
>
> This VBUS glitch might cause some USB devices emuration fail if kernel boot
> with them connected. One SW workaround which can fix this is to program
> all PORTSC[PP] to 0 to turn off VBUS immediately after setting host mode in
> DWC3 driver(per signal measurement result, it will be too late to do it in
> xhci-plat.c or xhci.c).
>
> Signed-off-by: Ran Wang <[email protected]>
> ---
> Documentation/devicetree/bindings/usb/dwc3.txt | 3 +++
> 1 files changed, 3 insertions(+), 0 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt
> b/Documentation/devicetree/bindings/usb/dwc3.txt
> index 8e5265e..dadb530 100644
> --- a/Documentation/devicetree/bindings/usb/dwc3.txt
> +++ b/Documentation/devicetree/bindings/usb/dwc3.txt
> @@ -106,6 +106,9 @@ Optional properties:
> When just one value, which means INCRX burst
> mode enabled. When
> more than one value, which means undefined length
> INCR burst type
> enabled. The values can be 1, 4, 8, 16, 32, 64, 128
> and 256.
> + - snps,avoid-vbus-glitch-when-set-host: Power off all Root Hub ports
> immediately
> + after setting host mode to avoid vbus (negative)
> glitch happen in later
> + xhci reset. And the vbus will back to 5V automatically
> when reset done.
>
> - in addition all properties from usb-xhci.txt from the current directory are
> supported as well
> --
> 1.7.1

Regards,
Ran


2019-01-16 18:27:46

by Ran Wang

[permalink] [raw]
Subject: [PATCH 2/2] usb: dwc3: Add workaround for host mode VBUS glitch when boot

When DWC3 is set to host mode by programming register DWC3_GCTL, VUBS
(or its control signal) will be turned on immediately on related Root Hub
ports. Then, the VUBS is turned off for a little while(15us) when do xhci
reset (conducted by xhci driver) and back to normal finally, we can
observed a negative glitch of related signal from scope.

This VBUS glitch might cause some USB devices enumeration fail if kernel
boot with them connected. Such as LS1012AFWRY/LS1043ARDB/LX2160AQDS
/LS1088ARDB with Kingston 16GB USB2.0/Kingston USB3.0/JetFlash Transcend
4GB USB2.0 drives. The fail cases include enumerated as full-speed device
or report wrong device descriptor, etc.

One SW workaround which can fix this is to program all xhci PORTSC[PP]
to 0 to turn off VBUS immediately after setting host mode in DWC3 driver
(per signal measurement result, it will be too late to do it in
xhci-plat.c or xhci.c). Then, after xhci reset complete in xhci driver,
PORTSC[PP]s' value will back to 1 automatically and VBUS on at that time,
no glitch happen and normal enumeration process has no impact.

Signed-off-by: Ran Wang <[email protected]>
---
drivers/usb/dwc3/core.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
drivers/usb/dwc3/core.h | 10 +++++++++-
2 files changed, 56 insertions(+), 1 deletions(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index a1b126f..1508397 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -100,6 +100,41 @@ static int dwc3_get_dr_mode(struct dwc3 *dwc)
return 0;
}

+/*
+ * dwc3_power_of_all_roothub_ports - Power off all Root hub ports
+ * @dwc3: Pointer to our controller context structure
+ */
+static void dwc3_power_off_all_roothub_ports(struct dwc3 *dwc)
+{
+ int i, port_num;
+ u32 reg, op_regs_base, offset;
+ void __iomem *xhci_regs;
+
+ /* xhci regs is not mapped yet, do it temperary here */
+ if (dwc->xhci_resources[0].start) {
+ xhci_regs = ioremap(dwc->xhci_resources[0].start,
+ DWC3_XHCI_REGS_END);
+ if (IS_ERR(xhci_regs)) {
+ dev_err(dwc->dev, "Failed to ioremap xhci_regs\n");
+ return;
+ }
+
+ op_regs_base = HC_LENGTH(readl(xhci_regs));
+ reg = readl(xhci_regs + XHCI_HCSPARAMS1);
+ port_num = HCS_MAX_PORTS(reg);
+
+ for (i = 1; i <= port_num; i++) {
+ offset = op_regs_base + XHCI_PORTSC_BASE + 0x10*(i-1);
+ reg = readl(xhci_regs + offset);
+ reg &= ~PORT_POWER;
+ writel(reg, xhci_regs + offset);
+ }
+
+ iounmap(xhci_regs);
+ } else
+ dev_err(dwc->dev, "xhci base reg invalid\n");
+}
+
void dwc3_set_prtcap(struct dwc3 *dwc, u32 mode)
{
u32 reg;
@@ -109,6 +144,15 @@ void dwc3_set_prtcap(struct dwc3 *dwc, u32 mode)
reg |= DWC3_GCTL_PRTCAPDIR(mode);
dwc3_writel(dwc->regs, DWC3_GCTL, reg);

+ /*
+ * We have to power off all Root hub ports immediately after DWC3 set
+ * to host mode to avoid VBUS glitch happen when xhci get reset later.
+ */
+ if (dwc->avoid_vbus_glitch_when_set_host) {
+ if (mode == DWC3_GCTL_PRTCAP_HOST)
+ dwc3_power_off_all_roothub_ports(dwc);
+ }
+
dwc->current_dr_role = mode;
}

@@ -1306,6 +1350,9 @@ static void dwc3_get_properties(struct dwc3 *dwc)
dwc->dis_metastability_quirk = device_property_read_bool(dev,
"snps,dis_metastability_quirk");

+ dwc->avoid_vbus_glitch_when_set_host = device_property_read_bool(dev,
+ "snps,avoid-vbus-glitch-when-set-host");
+
dwc->lpm_nyet_threshold = lpm_nyet_threshold;
dwc->tx_de_emphasis = tx_de_emphasis;

diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index df87641..691093b 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -606,6 +606,14 @@
#define DWC3_OSTS_VBUSVLD BIT(1)
#define DWC3_OSTS_CONIDSTS BIT(0)

+/* Partial XHCI Register and Bit fields for quirk */
+#define XHCI_HCSPARAMS1 0x4
+#define XHCI_PORTSC_BASE 0x400
+#define PORT_POWER (1 << 9)
+#define HCS_MAX_PORTS(p) (((p) >> 24) & 0x7f)
+#define XHCI_HC_LENGTH(p) (((p)>>00)&0x00ff)
+#define HC_LENGTH(p) XHCI_HC_LENGTH(p)
+
/* Structures */

struct dwc3_trb;
@@ -1209,6 +1217,7 @@ struct dwc3 {
unsigned tx_de_emphasis:2;

unsigned dis_metastability_quirk:1;
+ unsigned avoid_vbus_glitch_when_set_host:1;

u16 imod_interval;
};
@@ -1217,7 +1226,6 @@ struct dwc3 {
#define INCRX_UNDEF_LENGTH_BURST_MODE 1

#define work_to_dwc(w) (container_of((w), struct dwc3, drd_work))
-
/* -------------------------------------------------------------------------- */

struct dwc3_event_type {
--
1.7.1


2019-01-16 18:30:19

by Felipe Balbi

[permalink] [raw]
Subject: Re: [PATCH 2/2] usb: dwc3: Add workaround for host mode VBUS glitch when boot


Hi,

Ran Wang <[email protected]> writes:
> +static void dwc3_power_off_all_roothub_ports(struct dwc3 *dwc)
> +{
> + int i, port_num;
> + u32 reg, op_regs_base, offset;
> + void __iomem *xhci_regs;
> +
> + /* xhci regs is not mapped yet, do it temperary here */
> + if (dwc->xhci_resources[0].start) {
> + xhci_regs = ioremap(dwc->xhci_resources[0].start,
> + DWC3_XHCI_REGS_END);
> + if (IS_ERR(xhci_regs)) {
> + dev_err(dwc->dev, "Failed to ioremap xhci_regs\n");
> + return;
> + }
> +
> + op_regs_base = HC_LENGTH(readl(xhci_regs));
> + reg = readl(xhci_regs + XHCI_HCSPARAMS1);
> + port_num = HCS_MAX_PORTS(reg);
> +
> + for (i = 1; i <= port_num; i++) {
> + offset = op_regs_base + XHCI_PORTSC_BASE + 0x10*(i-1);
> + reg = readl(xhci_regs + offset);
> + reg &= ~PORT_POWER;
> + writel(reg, xhci_regs + offset);
> + }
> +
> + iounmap(xhci_regs);

why can't this be done during xhci_gen_setup()?

--
balbi


Attachments:
signature.asc (847.00 B)

2019-01-16 21:53:18

by kernel test robot

[permalink] [raw]
Subject: Re: [PATCH 2/2] usb: dwc3: Add workaround for host mode VBUS glitch when boot

Hi Ran,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on usb/usb-testing]
[also build test WARNING on v5.0-rc2 next-20190116]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url: https://github.com/0day-ci/linux/commits/Ran-Wang/usb-dwc3-Add-avoiding-vbus-glitch-happen-during-xhci-reset/20190116-153950
base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
reproduce: make htmldocs

All warnings (new ones prefixed by >>):

WARNING: convert(1) not found, for SVG to PDF conversion install ImageMagick (https://www.imagemagick.org)
include/linux/interrupt.h:268: warning: Function parameter or member 'is_managed' not described in 'irq_affinity_desc'
include/linux/rcupdate_wait.h:1: warning: no structured comments found
include/linux/rcutree.h:1: warning: no structured comments found
kernel/rcu/tree.c:710: warning: Excess function parameter 'irq' description in 'rcu_nmi_exit'
include/linux/gfp.h:1: warning: no structured comments found
include/net/cfg80211.h:4687: warning: Function parameter or member 'wext.ibss' not described in 'wireless_dev'
include/net/cfg80211.h:4687: warning: Function parameter or member 'wext.connect' not described in 'wireless_dev'
include/net/cfg80211.h:4687: warning: Function parameter or member 'wext.keys' not described in 'wireless_dev'
include/net/cfg80211.h:4687: warning: Function parameter or member 'wext.ie' not described in 'wireless_dev'
include/net/cfg80211.h:4687: warning: Function parameter or member 'wext.ie_len' not described in 'wireless_dev'
include/net/cfg80211.h:4687: warning: Function parameter or member 'wext.bssid' not described in 'wireless_dev'
include/net/cfg80211.h:4687: warning: Function parameter or member 'wext.ssid' not described in 'wireless_dev'
include/net/cfg80211.h:4687: warning: Function parameter or member 'wext.default_key' not described in 'wireless_dev'
include/net/cfg80211.h:4687: warning: Function parameter or member 'wext.default_mgmt_key' not described in 'wireless_dev'
include/net/cfg80211.h:4687: warning: Function parameter or member 'wext.prev_bssid_valid' not described in 'wireless_dev'
include/net/mac80211.h:2393: warning: Function parameter or member 'radiotap_timestamp.units_pos' not described in 'ieee80211_hw'
include/net/mac80211.h:2393: warning: Function parameter or member 'radiotap_timestamp.accuracy' not described in 'ieee80211_hw'
include/net/mac80211.h:1004: warning: Function parameter or member 'control.rates' not described in 'ieee80211_tx_info'
include/net/mac80211.h:1004: warning: Function parameter or member 'control.rts_cts_rate_idx' not described in 'ieee80211_tx_info'
include/net/mac80211.h:1004: warning: Function parameter or member 'control.use_rts' not described in 'ieee80211_tx_info'
include/net/mac80211.h:1004: warning: Function parameter or member 'control.use_cts_prot' not described in 'ieee80211_tx_info'
include/net/mac80211.h:1004: warning: Function parameter or member 'control.short_preamble' not described in 'ieee80211_tx_info'
include/net/mac80211.h:1004: warning: Function parameter or member 'control.skip_table' not described in 'ieee80211_tx_info'
include/net/mac80211.h:1004: warning: Function parameter or member 'control.jiffies' not described in 'ieee80211_tx_info'
include/net/mac80211.h:1004: warning: Function parameter or member 'control.vif' not described in 'ieee80211_tx_info'
include/net/mac80211.h:1004: warning: Function parameter or member 'control.hw_key' not described in 'ieee80211_tx_info'
include/net/mac80211.h:1004: warning: Function parameter or member 'control.flags' not described in 'ieee80211_tx_info'
include/net/mac80211.h:1004: warning: Function parameter or member 'control.enqueue_time' not described in 'ieee80211_tx_info'
include/net/mac80211.h:1004: warning: Function parameter or member 'ack' not described in 'ieee80211_tx_info'
include/net/mac80211.h:1004: warning: Function parameter or member 'ack.cookie' not described in 'ieee80211_tx_info'
include/net/mac80211.h:1004: warning: Function parameter or member 'status.rates' not described in 'ieee80211_tx_info'
include/net/mac80211.h:1004: warning: Function parameter or member 'status.ack_signal' not described in 'ieee80211_tx_info'
include/net/mac80211.h:1004: warning: Function parameter or member 'status.ampdu_ack_len' not described in 'ieee80211_tx_info'
include/net/mac80211.h:1004: warning: Function parameter or member 'status.ampdu_len' not described in 'ieee80211_tx_info'
include/net/mac80211.h:1004: warning: Function parameter or member 'status.antenna' not described in 'ieee80211_tx_info'
include/net/mac80211.h:1004: warning: Function parameter or member 'status.tx_time' not described in 'ieee80211_tx_info'
include/net/mac80211.h:1004: warning: Function parameter or member 'status.is_valid_ack_signal' not described in 'ieee80211_tx_info'
include/net/mac80211.h:1004: warning: Function parameter or member 'status.status_driver_data' not described in 'ieee80211_tx_info'
include/net/mac80211.h:1004: warning: Function parameter or member 'driver_rates' not described in 'ieee80211_tx_info'
include/net/mac80211.h:1004: warning: Function parameter or member 'pad' not described in 'ieee80211_tx_info'
include/net/mac80211.h:1004: warning: Function parameter or member 'rate_driver_data' not described in 'ieee80211_tx_info'
net/mac80211/sta_info.h:590: warning: Function parameter or member 'rx_stats_avg' not described in 'sta_info'
net/mac80211/sta_info.h:590: warning: Function parameter or member 'rx_stats_avg.signal' not described in 'sta_info'
net/mac80211/sta_info.h:590: warning: Function parameter or member 'rx_stats_avg.chain_signal' not described in 'sta_info'
net/mac80211/sta_info.h:590: warning: Function parameter or member 'status_stats.filtered' not described in 'sta_info'
net/mac80211/sta_info.h:590: warning: Function parameter or member 'status_stats.retry_failed' not described in 'sta_info'
net/mac80211/sta_info.h:590: warning: Function parameter or member 'status_stats.retry_count' not described in 'sta_info'
net/mac80211/sta_info.h:590: warning: Function parameter or member 'status_stats.lost_packets' not described in 'sta_info'
net/mac80211/sta_info.h:590: warning: Function parameter or member 'status_stats.last_tdls_pkt_time' not described in 'sta_info'
net/mac80211/sta_info.h:590: warning: Function parameter or member 'status_stats.msdu_retries' not described in 'sta_info'
net/mac80211/sta_info.h:590: warning: Function parameter or member 'status_stats.msdu_failed' not described in 'sta_info'
net/mac80211/sta_info.h:590: warning: Function parameter or member 'status_stats.last_ack' not described in 'sta_info'
net/mac80211/sta_info.h:590: warning: Function parameter or member 'status_stats.last_ack_signal' not described in 'sta_info'
net/mac80211/sta_info.h:590: warning: Function parameter or member 'status_stats.ack_signal_filled' not described in 'sta_info'
net/mac80211/sta_info.h:590: warning: Function parameter or member 'status_stats.avg_ack_signal' not described in 'sta_info'
net/mac80211/sta_info.h:590: warning: Function parameter or member 'tx_stats.packets' not described in 'sta_info'
net/mac80211/sta_info.h:590: warning: Function parameter or member 'tx_stats.bytes' not described in 'sta_info'
net/mac80211/sta_info.h:590: warning: Function parameter or member 'tx_stats.last_rate' not described in 'sta_info'
net/mac80211/sta_info.h:590: warning: Function parameter or member 'tx_stats.msdu' not described in 'sta_info'
kernel/rcu/tree.c:711: warning: Excess function parameter 'irq' description in 'rcu_nmi_exit'
include/linux/dma-buf.h:304: warning: Function parameter or member 'cb_excl.cb' not described in 'dma_buf'
include/linux/dma-buf.h:304: warning: Function parameter or member 'cb_excl.poll' not described in 'dma_buf'
include/linux/dma-buf.h:304: warning: Function parameter or member 'cb_excl.active' not described in 'dma_buf'
include/linux/dma-buf.h:304: warning: Function parameter or member 'cb_shared.cb' not described in 'dma_buf'
include/linux/dma-buf.h:304: warning: Function parameter or member 'cb_shared.poll' not described in 'dma_buf'
include/linux/dma-buf.h:304: warning: Function parameter or member 'cb_shared.active' not described in 'dma_buf'
include/linux/dma-fence-array.h:54: warning: Function parameter or member 'work' not described in 'dma_fence_array'
include/linux/firmware/intel/stratix10-svc-client.h:1: warning: no structured comments found
include/linux/gpio/driver.h:371: warning: Function parameter or member 'init_valid_mask' not described in 'gpio_chip'
include/linux/iio/hw-consumer.h:1: warning: no structured comments found
include/linux/input/sparse-keymap.h:46: warning: Function parameter or member 'sw' not described in 'key_entry'
drivers/mtd/nand/raw/nand_base.c:420: warning: Function parameter or member 'chip' not described in 'nand_fill_oob'
drivers/mtd/nand/raw/nand_bbt.c:173: warning: Function parameter or member 'this' not described in 'read_bbt'
drivers/mtd/nand/raw/nand_bbt.c:173: warning: Excess function parameter 'chip' description in 'read_bbt'
include/linux/regulator/machine.h:199: warning: Function parameter or member 'max_uV_step' not described in 'regulation_constraints'
include/linux/regulator/driver.h:228: warning: Function parameter or member 'resume' not described in 'regulator_ops'
arch/s390/include/asm/cio.h:245: warning: Function parameter or member 'esw.esw0' not described in 'irb'
arch/s390/include/asm/cio.h:245: warning: Function parameter or member 'esw.esw1' not described in 'irb'
arch/s390/include/asm/cio.h:245: warning: Function parameter or member 'esw.esw2' not described in 'irb'
arch/s390/include/asm/cio.h:245: warning: Function parameter or member 'esw.esw3' not described in 'irb'
arch/s390/include/asm/cio.h:245: warning: Function parameter or member 'esw.eadm' not described in 'irb'
drivers/slimbus/stream.c:1: warning: no structured comments found
include/linux/spi/spi.h:180: warning: Function parameter or member 'driver_override' not described in 'spi_device'
drivers/target/target_core_device.c:1: warning: no structured comments found
>> drivers/usb/dwc3/core.h:1224: warning: Function parameter or member 'avoid_vbus_glitch_when_set_host' not described in 'dwc3'
drivers/usb/typec/bus.c:1: warning: no structured comments found
drivers/usb/typec/class.c:1: warning: no structured comments found
include/linux/w1.h:281: warning: Function parameter or member 'of_match_table' not described in 'w1_family'
fs/direct-io.c:257: warning: Excess function parameter 'offset' description in 'dio_complete'
fs/file_table.c:1: warning: no structured comments found
fs/libfs.c:477: warning: Excess function parameter 'available' description in 'simple_write_end'
fs/posix_acl.c:646: warning: Function parameter or member 'inode' not described in 'posix_acl_update_mode'
fs/posix_acl.c:646: warning: Function parameter or member 'mode_p' not described in 'posix_acl_update_mode'
fs/posix_acl.c:646: warning: Function parameter or member 'acl' not described in 'posix_acl_update_mode'
drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c:294: warning: Excess function parameter 'mm' description in 'amdgpu_mn_invalidate_range_start_hsa'
drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c:294: warning: Excess function parameter 'start' description in 'amdgpu_mn_invalidate_range_start_hsa'
drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c:294: warning: Excess function parameter 'end' description in 'amdgpu_mn_invalidate_range_start_hsa'
drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c:343: warning: Excess function parameter 'mm' description in 'amdgpu_mn_invalidate_range_end'
drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c:343: warning: Excess function parameter 'start' description in 'amdgpu_mn_invalidate_range_end'
drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c:343: warning: Excess function parameter 'end' description in 'amdgpu_mn_invalidate_range_end'
drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c:183: warning: Function parameter or member 'blockable' not described in 'amdgpu_mn_read_lock'
drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c:295: warning: Function parameter or member 'range' not described in 'amdgpu_mn_invalidate_range_start_hsa'
drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c:295: warning: Excess function parameter 'mm' description in 'amdgpu_mn_invalidate_range_start_hsa'
drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c:295: warning: Excess function parameter 'start' description in 'amdgpu_mn_invalidate_range_start_hsa'
drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c:295: warning: Excess function parameter 'end' description in 'amdgpu_mn_invalidate_range_start_hsa'
drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c:344: warning: Function parameter or member 'range' not described in 'amdgpu_mn_invalidate_range_end'
drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c:344: warning: Excess function parameter 'mm' description in 'amdgpu_mn_invalidate_range_end'
drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c:344: warning: Excess function parameter 'start' description in 'amdgpu_mn_invalidate_range_end'
drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c:344: warning: Excess function parameter 'end' description in 'amdgpu_mn_invalidate_range_end'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:382: warning: cannot understand function prototype: 'struct amdgpu_vm_pt_cursor '
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:383: warning: cannot understand function prototype: 'struct amdgpu_vm_pt_cursor '
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:555: warning: Function parameter or member 'adev' not described in 'for_each_amdgpu_vm_pt_leaf'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:555: warning: Function parameter or member 'vm' not described in 'for_each_amdgpu_vm_pt_leaf'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:555: warning: Function parameter or member 'start' not described in 'for_each_amdgpu_vm_pt_leaf'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:555: warning: Function parameter or member 'end' not described in 'for_each_amdgpu_vm_pt_leaf'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:555: warning: Function parameter or member 'cursor' not described in 'for_each_amdgpu_vm_pt_leaf'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:603: warning: Function parameter or member 'adev' not described in 'for_each_amdgpu_vm_pt_dfs_safe'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:603: warning: Function parameter or member 'vm' not described in 'for_each_amdgpu_vm_pt_dfs_safe'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:603: warning: Function parameter or member 'cursor' not described in 'for_each_amdgpu_vm_pt_dfs_safe'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:603: warning: Function parameter or member 'entry' not described in 'for_each_amdgpu_vm_pt_dfs_safe'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:845: warning: Function parameter or member 'level' not described in 'amdgpu_vm_bo_param'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1350: warning: Function parameter or member 'params' not described in 'amdgpu_vm_update_func'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1350: warning: Function parameter or member 'bo' not described in 'amdgpu_vm_update_func'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1350: warning: Function parameter or member 'pe' not described in 'amdgpu_vm_update_func'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1350: warning: Function parameter or member 'addr' not described in 'amdgpu_vm_update_func'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1350: warning: Function parameter or member 'count' not described in 'amdgpu_vm_update_func'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1350: warning: Function parameter or member 'incr' not described in 'amdgpu_vm_update_func'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1350: warning: Function parameter or member 'flags' not described in 'amdgpu_vm_update_func'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1517: warning: Function parameter or member 'params' not described in 'amdgpu_vm_update_huge'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1517: warning: Function parameter or member 'bo' not described in 'amdgpu_vm_update_huge'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1517: warning: Function parameter or member 'level' not described in 'amdgpu_vm_update_huge'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1517: warning: Function parameter or member 'pe' not described in 'amdgpu_vm_update_huge'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1517: warning: Function parameter or member 'addr' not described in 'amdgpu_vm_update_huge'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1517: warning: Function parameter or member 'count' not described in 'amdgpu_vm_update_huge'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1517: warning: Function parameter or member 'incr' not described in 'amdgpu_vm_update_huge'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1517: warning: Function parameter or member 'flags' not described in 'amdgpu_vm_update_huge'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:3093: warning: Function parameter or member 'pasid' not described in 'amdgpu_vm_make_compute'
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h:128: warning: Incorrect use of kernel-doc format: Documentation Makefile include scripts source @atomic_obj
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h:203: warning: Function parameter or member 'atomic_obj' not described in 'amdgpu_display_manager'
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h:203: warning: Function parameter or member 'atomic_obj_lock' not described in 'amdgpu_display_manager'
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h:203: warning: Function parameter or member 'backlight_link' not described in 'amdgpu_display_manager'
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h:203: warning: Function parameter or member 'backlight_caps' not described in 'amdgpu_display_manager'
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h:203: warning: Function parameter or member 'freesync_module' not described in 'amdgpu_display_manager'
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h:203: warning: Function parameter or member 'fw_dmcu' not described in 'amdgpu_display_manager'
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h:203: warning: Function parameter or member 'dmcu_fw_version' not described in 'amdgpu_display_manager'
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c:1: warning: no structured comments found
include/drm/drm_drv.h:618: warning: Function parameter or member 'gem_prime_pin' not described in 'drm_driver'
include/drm/drm_drv.h:618: warning: Function parameter or member 'gem_prime_unpin' not described in 'drm_driver'
include/drm/drm_drv.h:618: warning: Function parameter or member 'gem_prime_res_obj' not described in 'drm_driver'
include/drm/drm_drv.h:618: warning: Function parameter or member 'gem_prime_get_sg_table' not described in 'drm_driver'
include/drm/drm_drv.h:618: warning: Function parameter or member 'gem_prime_import_sg_table' not described in 'drm_driver'
include/drm/drm_drv.h:618: warning: Function parameter or member 'gem_prime_vmap' not described in 'drm_driver'
include/drm/drm_drv.h:618: warning: Function parameter or member 'gem_prime_vunmap' not described in 'drm_driver'
include/drm/drm_drv.h:618: warning: Function parameter or member 'gem_prime_mmap' not described in 'drm_driver'
include/drm/drm_atomic_state_helper.h:1: warning: no structured comments found
drivers/gpu/drm/drm_dp_helper.c:1364: warning: Function parameter or member 'dsc_dpcd' not described in 'drm_dp_dsc_sink_max_slice_count'
drivers/gpu/drm/drm_dp_helper.c:1364: warning: Function parameter or member 'is_edp' not described in 'drm_dp_dsc_sink_max_slice_count'
drivers/gpu/drm/i915/i915_vma.h:49: warning: cannot understand function prototype: 'struct i915_vma '
drivers/gpu/drm/i915/i915_vma.h:1: warning: no structured comments found
drivers/gpu/drm/i915/intel_guc_fwif.h:536: warning: cannot understand function prototype: 'struct guc_log_buffer_state '
drivers/gpu/drm/i915/i915_trace.h:1: warning: no structured comments found
include/linux/skbuff.h:876: warning: Function parameter or member 'dev_scratch' not described in 'sk_buff'
include/linux/skbuff.h:876: warning: Function parameter or member 'list' not described in 'sk_buff'
include/linux/skbuff.h:876: warning: Function parameter or member 'ip_defrag_offset' not described in 'sk_buff'
include/linux/skbuff.h:876: warning: Function parameter or member 'skb_mstamp_ns' not described in 'sk_buff'
include/linux/skbuff.h:876: warning: Function parameter or member '__cloned_offset' not described in 'sk_buff'
include/linux/skbuff.h:876: warning: Function parameter or member 'head_frag' not described in 'sk_buff'
include/linux/skbuff.h:876: warning: Function parameter or member '__pkt_type_offset' not described in 'sk_buff'
include/linux/skbuff.h:876: warning: Function parameter or member 'encapsulation' not described in 'sk_buff'
include/linux/skbuff.h:876: warning: Function parameter or member 'encap_hdr_csum' not described in 'sk_buff'
include/linux/skbuff.h:876: warning: Function parameter or member 'csum_valid' not described in 'sk_buff'
include/linux/skbuff.h:876: warning: Function parameter or member '__pkt_vlan_present_offset' not described in 'sk_buff'
include/linux/skbuff.h:876: warning: Function parameter or member 'vlan_present' not described in 'sk_buff'
include/linux/skbuff.h:876: warning: Function parameter or member 'csum_complete_sw' not described in 'sk_buff'
include/linux/skbuff.h:876: warning: Function parameter or member 'csum_level' not described in 'sk_buff'
include/linux/skbuff.h:876: warning: Function parameter or member 'inner_protocol_type' not described in 'sk_buff'
include/linux/skbuff.h:876: warning: Function parameter or member 'remcsum_offload' not described in 'sk_buff'
include/linux/skbuff.h:876: warning: Function parameter or member 'sender_cpu' not described in 'sk_buff'
include/linux/skbuff.h:876: warning: Function parameter or member 'reserved_tailroom' not described in 'sk_buff'
include/linux/skbuff.h:876: warning: Function parameter or member 'inner_ipproto' not described in 'sk_buff'
include/net/sock.h:238: warning: Function parameter or member 'skc_addrpair' not described in 'sock_common'
include/net/sock.h:238: warning: Function parameter or member 'skc_portpair' not described in 'sock_common'
include/net/sock.h:238: warning: Function parameter or member 'skc_ipv6only' not described in 'sock_common'
include/net/sock.h:238: warning: Function parameter or member 'skc_net_refcnt' not described in 'sock_common'
include/net/sock.h:238: warning: Function parameter or member 'skc_v6_daddr' not described in 'sock_common'

vim +1224 drivers/usb/dwc3/core.h

72246da4 Felipe Balbi 2011-08-19 @1224

:::::: The code at line 1224 was first introduced by commit
:::::: 72246da40f3719af3bfd104a2365b32537c27d83 usb: Introduce DesignWare USB3 DRD Driver

:::::: TO: Felipe Balbi <[email protected]>
:::::: CC: Greg Kroah-Hartman <[email protected]>

---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation


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2019-01-22 01:05:21

by Rob Herring (Arm)

[permalink] [raw]
Subject: Re: [PATCH 1/2] usb: dwc3: Add avoiding vbus glitch happen during xhci reset

On Wed, Jan 16, 2019 at 06:48:06AM +0000, Ran Wang wrote:
> When DWC3 is set to host mode by programming register DWC3_GCTL, VUBS

s/VUBS/VBUS/

> (or its control signal) will on immediately on related Root Hub ports.

/will on/will turn on/

> Then the VUBS will be de-asserted for a little while during xhci
> reset (conducted by xhci driver) for a little while and back to normal.
>
> This VBUS glitch might cause some USB devices emuration fail if kernel boot
> with them connected. One SW workaround which can fix this is to program
> all PORTSC[PP] to 0 to turn off VBUS immediately after setting host mode
> in DWC3 driver(per signal measurement result, it will be too late to do
> it in xhci-plat.c or xhci.c).
>
> Signed-off-by: Ran Wang <[email protected]>
> ---
> Documentation/devicetree/bindings/usb/dwc3.txt | 3 +++
> 1 files changed, 3 insertions(+), 0 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt
> index 8e5265e..dadb530 100644
> --- a/Documentation/devicetree/bindings/usb/dwc3.txt
> +++ b/Documentation/devicetree/bindings/usb/dwc3.txt
> @@ -106,6 +106,9 @@ Optional properties:
> When just one value, which means INCRX burst mode enabled. When
> more than one value, which means undefined length INCR burst type
> enabled. The values can be 1, 4, 8, 16, 32, 64, 128 and 256.
> + - snps,avoid-vbus-glitch-when-set-host: Power off all Root Hub ports immediately
> + after setting host mode to avoid vbus (negative) glitch happen in later
> + xhci reset. And the vbus will back to 5V automatically when reset done.

Can't you imply this from the compatible string. You should have an SoC
specific compatible.

Does this even need to be conditional? What would be the harm in doing
this unconditionally for all DWC3 hosts?

Rob

2019-01-22 02:39:57

by Ran Wang

[permalink] [raw]
Subject: RE: [PATCH 1/2] usb: dwc3: Add avoiding vbus glitch happen during xhci reset

Hi Rob,

On January 22, 2019 09:03, Rob Herring wrote:
>
> On Wed, Jan 16, 2019 at 06:48:06AM +0000, Ran Wang wrote:
> > When DWC3 is set to host mode by programming register DWC3_GCTL,
> VUBS
>
> s/VUBS/VBUS/

Yes, will fix it in next version.

> > (or its control signal) will on immediately on related Root Hub ports.
>
> /will on/will turn on/

Got it. Thanks.

> > Then the VUBS will be de-asserted for a little while during xhci reset
> > (conducted by xhci driver) for a little while and back to normal.
> >
> > This VBUS glitch might cause some USB devices emuration fail if kernel
> > boot with them connected. One SW workaround which can fix this is to
> > program all PORTSC[PP] to 0 to turn off VBUS immediately after setting
> > host mode in DWC3 driver(per signal measurement result, it will be too
> > late to do it in xhci-plat.c or xhci.c).
> >
> > Signed-off-by: Ran Wang <[email protected]>
> > ---
> > Documentation/devicetree/bindings/usb/dwc3.txt | 3 +++
> > 1 files changed, 3 insertions(+), 0 deletions(-)
> >
> > diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt
> > b/Documentation/devicetree/bindings/usb/dwc3.txt
> > index 8e5265e..dadb530 100644
> > --- a/Documentation/devicetree/bindings/usb/dwc3.txt
> > +++ b/Documentation/devicetree/bindings/usb/dwc3.txt
> > @@ -106,6 +106,9 @@ Optional properties:
> > When just one value, which means INCRX burst
> mode enabled. When
> > more than one value, which means undefined length
> INCR burst type
> > enabled. The values can be 1, 4, 8, 16, 32, 64, 128
> and 256.
> > + - snps,avoid-vbus-glitch-when-set-host: Power off all Root Hub ports
> immediately
> > + after setting host mode to avoid vbus (negative)
> glitch happen in later
> > + xhci reset. And the vbus will back to 5V automatically
> when reset done.
>
> Can't you imply this from the compatible string. You should have an SoC
> specific compatible.

Sorry, not quite get your point here? Actually I have discussed with Soc design guys
and Felipe, it seems to be DWC3 native behavior rather than SoC specific issue.
https://lkml.org/lkml/2018/11/23/387
https://lkml.org/lkml/2018/12/12/140

I think there could be 2 reasons why we got no report for a long time till now:
1. Most USB devices are not so sensitive to this VBUS glitch, they would works fine.
2. A proper VBUS pump circuit design can successfully filter this glitch out. I have
confirmed this with scope, which means some platforms might resolve issue in
this way already (some might not, of cause).

> Does this even need to be conditional? What would be the harm in doing
> this unconditionally for all DWC3 hosts?

From the logic level, I don't see a harm to DWC3 hosts if unconditionally apply this.
However, since this is not a only solution (can fix it in HW way), I prefer to let it
controlled by property in DTS node for those questionable board already existing
in market.

Regards,
Ran


2019-01-22 13:47:25

by Rob Herring (Arm)

[permalink] [raw]
Subject: Re: [PATCH 1/2] usb: dwc3: Add avoiding vbus glitch happen during xhci reset

On Mon, Jan 21, 2019 at 8:38 PM Ran Wang <[email protected]> wrote:
>
> Hi Rob,
>
> On January 22, 2019 09:03, Rob Herring wrote:
> >
> > On Wed, Jan 16, 2019 at 06:48:06AM +0000, Ran Wang wrote:
> > > When DWC3 is set to host mode by programming register DWC3_GCTL,
> > VUBS
> >
> > s/VUBS/VBUS/
>
> Yes, will fix it in next version.
>
> > > (or its control signal) will on immediately on related Root Hub ports.
> >
> > /will on/will turn on/
>
> Got it. Thanks.
>
> > > Then the VUBS will be de-asserted for a little while during xhci reset
> > > (conducted by xhci driver) for a little while and back to normal.
> > >
> > > This VBUS glitch might cause some USB devices emuration fail if kernel
> > > boot with them connected. One SW workaround which can fix this is to
> > > program all PORTSC[PP] to 0 to turn off VBUS immediately after setting
> > > host mode in DWC3 driver(per signal measurement result, it will be too
> > > late to do it in xhci-plat.c or xhci.c).
> > >
> > > Signed-off-by: Ran Wang <[email protected]>
> > > ---
> > > Documentation/devicetree/bindings/usb/dwc3.txt | 3 +++
> > > 1 files changed, 3 insertions(+), 0 deletions(-)
> > >
> > > diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt
> > > b/Documentation/devicetree/bindings/usb/dwc3.txt
> > > index 8e5265e..dadb530 100644
> > > --- a/Documentation/devicetree/bindings/usb/dwc3.txt
> > > +++ b/Documentation/devicetree/bindings/usb/dwc3.txt
> > > @@ -106,6 +106,9 @@ Optional properties:
> > > When just one value, which means INCRX burst
> > mode enabled. When
> > > more than one value, which means undefined length
> > INCR burst type
> > > enabled. The values can be 1, 4, 8, 16, 32, 64, 128
> > and 256.
> > > + - snps,avoid-vbus-glitch-when-set-host: Power off all Root Hub ports
> > immediately
> > > + after setting host mode to avoid vbus (negative)
> > glitch happen in later
> > > + xhci reset. And the vbus will back to 5V automatically
> > when reset done.
> >
> > Can't you imply this from the compatible string. You should have an SoC
> > specific compatible.
>
> Sorry, not quite get your point here? Actually I have discussed with Soc design guys
> and Felipe, it seems to be DWC3 native behavior rather than SoC specific issue.
> https://lkml.org/lkml/2018/11/23/387
> https://lkml.org/lkml/2018/12/12/140
>
> I think there could be 2 reasons why we got no report for a long time till now:
> 1. Most USB devices are not so sensitive to this VBUS glitch, they would works fine.
> 2. A proper VBUS pump circuit design can successfully filter this glitch out. I have
> confirmed this with scope, which means some platforms might resolve issue in
> this way already (some might not, of cause).
>
> > Does this even need to be conditional? What would be the harm in doing
> > this unconditionally for all DWC3 hosts?
>
> From the logic level, I don't see a harm to DWC3 hosts if unconditionally apply this.
> However, since this is not a only solution (can fix it in HW way), I prefer to let it
> controlled by property in DTS node for those questionable board already existing
> in market.

Okay, sounds fine.

I would shorten the name a bit: snps,host-vbus-glitches

Rob

2019-02-15 15:38:36

by Ran Wang

[permalink] [raw]
Subject: RE: [PATCH 2/2] usb: dwc3: Add workaround for host mode VBUS glitch when boot

Hi Felipe,

Sorry for the late response, I didn't receive your mail.

Felipe Balbi <[email protected]> wrotes:
>Hi,
>
>Ran Wang <[email protected]> writes:
>> +static void dwc3_power_off_all_roothub_ports(struct dwc3 *dwc)
>> +{
>> + int i, port_num;
>> + u32 reg, op_regs_base, offset;
>> + void __iomem *xhci_regs;
>> +
>> + /* xhci regs is not mapped yet, do it temperary here */
>> + if (dwc->xhci_resources[0].start) {
>> + xhci_regs = ioremap(dwc->xhci_resources[0].start,
>> + DWC3_XHCI_REGS_END);
>> + if (IS_ERR(xhci_regs)) {
>> + dev_err(dwc->dev, "Failed to ioremap xhci_regs\n");
>> + return;
>> + }
>> +
>> + op_regs_base = HC_LENGTH(readl(xhci_regs));
>> + reg = readl(xhci_regs + XHCI_HCSPARAMS1);
>> + port_num = HCS_MAX_PORTS(reg);
>> +
>> + for (i = 1; i <= port_num; i++) {
>> + offset = op_regs_base + XHCI_PORTSC_BASE + 0x10*(i-1);
>> + reg = readl(xhci_regs + offset);
>> + reg &= ~PORT_POWER;
>> + writel(reg, xhci_regs + offset);
>> + }
>> +
>> + iounmap(xhci_regs);
>
>why can't this be done during xhci_gen_setup()?

Actually I have done experiment like what you suggested (in xhci-plat.c), but the timing
seems too late--making VBUS waveform look like a square wave as below:

Here DWC3 enable host mode, VBUS on
|
+5V /---------\ 40ms /---------------------------....
0V ________/ 90ms \______/
| |
| Here do xhci reset, VBUS back to +5V again
Here set all PORTSC[PP] to 0 in xhci_gen_setup()

So I am afraid the solution might have to be added in DWC3 core driver where just after host mode enabling code if want fix this :(

Regards,
Ran