2018-10-22 18:37:53

by Aaron Ma

[permalink] [raw]
Subject: [PATCH v2 1/2] usb: xhci: fix uninitialized completion when USB3 port got wrong status

Realtek USB3.0 Card Reader [0bda:0328] reports wrong port status on
Cannon lake PCH USB3.1 xHCI [8086:a36d] after resume from S3,
after clear port reset it works fine.

Since this device is registered on USB3 roothub at boot,
when port status reports not superspeed, xhci_get_port_status will call
an uninitialized completion in bus_state[0].
Kernel will hang because of NULL pointer.

Restrict the USB2 resume status check in USB2 roothub to fix hang issue.

Cc: [email protected]
Signed-off-by: Aaron Ma <[email protected]>
---
drivers/usb/host/xhci-hub.c | 2 +-
drivers/usb/host/xhci-ring.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index 7e2a531ba321..56a08daa7431 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -876,7 +876,7 @@ static u32 xhci_get_port_status(struct usb_hcd *hcd,
status |= USB_PORT_STAT_SUSPEND;
}
if ((raw_port_status & PORT_PLS_MASK) == XDEV_RESUME &&
- !DEV_SUPERSPEED_ANY(raw_port_status)) {
+ !DEV_SUPERSPEED_ANY(raw_port_status) && hcd->speed < HCD_USB3) {
if ((raw_port_status & PORT_RESET) ||
!(raw_port_status & PORT_PE))
return 0xffffffff;
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index f0a99aa0ac58..7318fc422b6c 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1634,7 +1634,7 @@ static void handle_port_status(struct xhci_hcd *xhci,
* RExit to a disconnect state). If so, let the the driver know it's
* out of the RExit state.
*/
- if (!DEV_SUPERSPEED_ANY(portsc) &&
+ if (!DEV_SUPERSPEED_ANY(portsc) && hcd->speed < HCD_USB3 &&
test_and_clear_bit(hcd_portnum,
&bus_state->rexit_ports)) {
complete(&bus_state->rexit_done[hcd_portnum]);
--
2.19.1



2018-10-22 18:39:32

by Aaron Ma

[permalink] [raw]
Subject: [PATCH v2 2/2] usb: xhci: fix timeout for transition from RExit to U0

This definition is used by msecs_to_jiffies in milliseconds.
According to the comments, max rexit timeout should be 20ms.
Align with the comments to properly calculate the delay.

Verified on Sunrise Point-LP and Cannon Lake.

Cc: [email protected]
Signed-off-by: Aaron Ma <[email protected]>
---
drivers/usb/host/xhci-hub.c | 4 ++--
drivers/usb/host/xhci.h | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index 56a08daa7431..af168ada8f86 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -920,7 +920,7 @@ static u32 xhci_get_port_status(struct usb_hcd *hcd,
time_left = wait_for_completion_timeout(
&bus_state->rexit_done[wIndex],
msecs_to_jiffies(
- XHCI_MAX_REXIT_TIMEOUT));
+ XHCI_MAX_REXIT_TIMEOUT_MS));
spin_lock_irqsave(&xhci->lock, flags);

if (time_left) {
@@ -934,7 +934,7 @@ static u32 xhci_get_port_status(struct usb_hcd *hcd,
} else {
int port_status = readl(port->addr);
xhci_warn(xhci, "Port resume took longer than %i msec, port status = 0x%x\n",
- XHCI_MAX_REXIT_TIMEOUT,
+ XHCI_MAX_REXIT_TIMEOUT_MS,
port_status);
status |= USB_PORT_STAT_SUSPEND;
clear_bit(wIndex, &bus_state->rexit_ports);
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 6230a578324c..237877042262 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1678,7 +1678,7 @@ struct xhci_bus_state {
* It can take up to 20 ms to transition from RExit to U0 on the
* Intel Lynx Point LP xHCI host.
*/
-#define XHCI_MAX_REXIT_TIMEOUT (20 * 1000)
+#define XHCI_MAX_REXIT_TIMEOUT_MS 20

static inline unsigned int hcd_index(struct usb_hcd *hcd)
{
--
2.19.1


2018-10-23 10:41:00

by Mathias Nyman

[permalink] [raw]
Subject: Re: [PATCH v2 2/2] usb: xhci: fix timeout for transition from RExit to U0

On 22.10.2018 20:42, Aaron Ma wrote:
> This definition is used by msecs_to_jiffies in milliseconds.
> According to the comments, max rexit timeout should be 20ms.
> Align with the comments to properly calculate the delay.
>
> Verified on Sunrise Point-LP and Cannon Lake.
>
> Cc: [email protected]
> Signed-off-by: Aaron Ma <[email protected]>

Thanks, adding to queue, will send forward after rc1

-Mathias

2018-10-23 10:41:24

by Mathias Nyman

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] usb: xhci: fix uninitialized completion when USB3 port got wrong status

On 22.10.2018 20:42, Aaron Ma wrote:
> Realtek USB3.0 Card Reader [0bda:0328] reports wrong port status on
> Cannon lake PCH USB3.1 xHCI [8086:a36d] after resume from S3,
> after clear port reset it works fine.
>
> Since this device is registered on USB3 roothub at boot,
> when port status reports not superspeed, xhci_get_port_status will call
> an uninitialized completion in bus_state[0].
> Kernel will hang because of NULL pointer.
>
> Restrict the USB2 resume status check in USB2 roothub to fix hang issue.
>
> Cc: [email protected]
> Signed-off-by: Aaron Ma <[email protected]>

Thanks, adding to queue, will send forward after rc1

-Mathias