LinuxLists.cc - [PATCH AUTOSEL 5.15 01/31] phy: qcom-snps-femto-v2: keep cfg_ahb

2023-08-13 16:30:08

Subject: [PATCH AUTOSEL 5.15 01/31] phy: qcom-snps-femto-v2: keep cfg_ahb_clk enabled during runtime suspend

From: Adrien Thierry <[email protected]>

[ Upstream commit 45d89a344eb46db9dce851c28e14f5e3c635c251 ]

In the dwc3 core, both system and runtime suspend end up calling
dwc3_suspend_common(). From there, what happens for the PHYs depends on
the USB mode and whether the controller is entering system or runtime
suspend.

HOST mode:
(1) system suspend on a non-wakeup-capable controller

The [1] if branch is taken. dwc3_core_exit() is called, which ends up
calling phy_power_off() and phy_exit(). Those two functions decrease the
PM runtime count at some point, so they will trigger the PHY runtime
sleep (assuming the count is right).

(2) runtime suspend / system suspend on a wakeup-capable controller

The [1] branch is not taken. dwc3_suspend_common() calls
phy_pm_runtime_put_sync(). Assuming the ref count is right, the PHY
runtime suspend op is called.

DEVICE mode:
dwc3_core_exit() is called on both runtime and system sleep
unless the controller is already runtime suspended.

OTG mode:
(1) system suspend : dwc3_core_exit() is called

(2) runtime suspend : do nothing

In host mode, the code seems to make a distinction between 1) runtime
sleep / system sleep for wakeup-capable controller, and 2) system sleep
for non-wakeup-capable controller, where phy_power_off() and phy_exit()
are only called for the latter. This suggests the PHY is not supposed to
be in a fully powered-off state for runtime sleep and system sleep for
wakeup-capable controller.

Moreover, downstream, cfg_ahb_clk only gets disabled for system suspend.
The clocks are disabled by phy->set_suspend() [2] which is only called
in the system sleep path through dwc3_core_exit() [3].

With that in mind, don't disable the clocks during the femto PHY runtime
suspend callback. The clocks will only be disabled during system suspend
for non-wakeup-capable controllers, through dwc3_core_exit().

[1] https://elixir.bootlin.com/linux/v6.4/source/drivers/usb/dwc3/core.c#L1988
[2] https://git.codelinaro.org/clo/la/kernel/msm-5.4/-/blob/LV.AU.1.2.1.r2-05300-gen3meta.0/drivers/usb/phy/phy-msm-snps-hs.c#L524
[3] https://git.codelinaro.org/clo/la/kernel/msm-5.4/-/blob/LV.AU.1.2.1.r2-05300-gen3meta.0/drivers/usb/dwc3/core.c#L1915

Signed-off-by: Adrien Thierry <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Vinod Koul <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
---
drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c | 9 ---------
1 file changed, 9 deletions(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c b/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c
index 7e61202aa234e..a107f98c662d5 100644
--- a/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c
+++ b/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c
@@ -122,22 +122,13 @@ static int qcom_snps_hsphy_suspend(struct qcom_snps_hsphy *hsphy)
0, USB2_AUTO_RESUME);
}

- clk_disable_unprepare(hsphy->cfg_ahb_clk);
return 0;
}

static int qcom_snps_hsphy_resume(struct qcom_snps_hsphy *hsphy)
{
- int ret;
-
dev_dbg(&hsphy->phy->dev, "Resume QCOM SNPS PHY, mode\n");

- ret = clk_prepare_enable(hsphy->cfg_ahb_clk);
- if (ret) {
- dev_err(&hsphy->phy->dev, "failed to enable cfg ahb clock\n");
- return ret;
- }
-
return 0;
}

--
2.40.1

2023-08-13 16:30:21

Subject: [PATCH AUTOSEL 5.15 01/31] phy: qcom-snps-femto-v2: keep cfg_ahb_clk enabled during runtime suspend

Subject: [PATCH AUTOSEL 5.15 04/31] media: pci: cx23885: fix error handling for cx23885 ATSC boards

Subject: [PATCH AUTOSEL 5.15 31/31] kprobes: Prohibit probing on CFI preamble symbol

Subject: [PATCH AUTOSEL 5.15 25/31] drm/amd/display: Exit idle optimizations before attempt to access PHY

Subject: [PATCH AUTOSEL 5.15 02/31] phy: qcom-snps-femto-v2: use qcom_snps_hsphy_suspend/resume error code

Subject: [PATCH AUTOSEL 5.15 29/31] rbd: harden get_lock_owner_info() a bit

Subject: [PATCH AUTOSEL 5.15 07/31] ksmbd: no response from compound read

Subject: [PATCH AUTOSEL 5.15 20/31] ASoC: atmel: Fix the 8K sample parameter in I2SC master

Subject: [PATCH AUTOSEL 5.15 03/31] media: pulse8-cec: handle possible ping error

Subject: [PATCH AUTOSEL 5.15 30/31] security: keys: perform capable check only on privileged operations

Subject: [PATCH AUTOSEL 5.15 23/31] platform/x86/intel/hid: Add HP Dragonfly G2 to VGBS DMI quirks

Subject: [PATCH AUTOSEL 5.15 14/31] s390/dasd: fix hanging device after request requeue

Subject: [PATCH AUTOSEL 5.15 08/31] ASoC: da7219: Flush pending AAD IRQ when suspending

Subject: [PATCH AUTOSEL 5.15 11/31] vxlan: generalize vxlan_parse_gpe_hdr and remove unused args

Subject: [PATCH AUTOSEL 5.15 27/31] ata: pata_arasan_cf: Use dev_err_probe() instead dev_err() in data_xfer()

Subject: [PATCH AUTOSEL 5.15 28/31] rbd: make get_lock_owner_info() return a single locker or NULL

Subject: [PATCH AUTOSEL 5.15 05/31] 9p: virtio: make sure 'offs' is initialized in zc_request

Subject: [PATCH AUTOSEL 5.15 15/31] fs/nls: make load_nls() take a const parameter

Subject: [PATCH AUTOSEL 5.15 21/31] ALSA: usb-audio: Add quirk for Microsoft Modern Wireless Headset

Subject: [PATCH AUTOSEL 5.15 12/31] m68k: Fix invalid .section syntax

Subject: [PATCH AUTOSEL 5.15 13/31] s390/dasd: use correct number of retries for ERP requests

Subject: Re: [PATCH AUTOSEL 5.15 28/31] rbd: make get_lock_owner_info() return a single locker or NULL