This is a note to let you know that I've just added the patch titled
usb: dwc2: fix a devres leak in hw_enable upon suspend resume
to the 6.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
usb-dwc2-fix-a-devres-leak-in-hw_enable-upon-suspend-resume.patch
and it can be found in the queue-6.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From f747313249b74f323ddf841a9c8db14d989f296a Mon Sep 17 00:00:00 2001
From: Fabrice Gasnier <fabrice.gasnier@xxxxxxxxxxx>
Date: Thu, 16 Mar 2023 09:41:27 +0100
Subject: usb: dwc2: fix a devres leak in hw_enable upon suspend resume
From: Fabrice Gasnier <fabrice.gasnier@xxxxxxxxxxx>
commit f747313249b74f323ddf841a9c8db14d989f296a upstream.
Each time the platform goes to low power, PM suspend / resume routines
call: __dwc2_lowlevel_hw_enable -> devm_add_action_or_reset().
This adds a new devres each time.
This may also happen at runtime, as dwc2_lowlevel_hw_enable() can be
called from udc_start().
This can be seen with tracing:
- echo 1 > /sys/kernel/debug/tracing/events/dev/devres_log/enable
- go to low power
- cat /sys/kernel/debug/tracing/trace
A new "ADD" entry is found upon each low power cycle:
... devres_log: 49000000.usb-otg ADD 82a13bba devm_action_release (8 bytes)
... devres_log: 49000000.usb-otg ADD 49889daf devm_action_release (8 bytes)
...
A second issue is addressed here:
- regulator_bulk_enable() is called upon each PM cycle (suspend/resume).
- regulator_bulk_disable() never gets called.
So the reference count for these regulators constantly increase, by one
upon each low power cycle, due to missing regulator_bulk_disable() call
in __dwc2_lowlevel_hw_disable().
The original fix that introduced the devm_add_action_or_reset() call,
fixed an issue during probe, that happens due to other errors in
dwc2_driver_probe() -> dwc2_core_reset(). Then the probe fails without
disabling regulators, when dr_mode == USB_DR_MODE_PERIPHERAL.
Rather fix the error path: disable all the low level hardware in the
error path, by using the "hsotg->ll_hw_enabled" flag. Checking dr_mode
has been introduced to avoid a dual call to dwc2_lowlevel_hw_disable().
"ll_hw_enabled" should achieve the same (and is used currently in the
remove() routine).
Fixes: 54c196060510 ("usb: dwc2: Always disable regulators on driver teardown")
Fixes: 33a06f1300a7 ("usb: dwc2: Fix error path in gadget registration")
Cc: stable <stable@xxxxxxxxxx>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230316084127.126084-1-fabrice.gasnier@xxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/dwc2/platform.c | 16 ++--------------
1 file changed, 2 insertions(+), 14 deletions(-)
--- a/drivers/usb/dwc2/platform.c
+++ b/drivers/usb/dwc2/platform.c
@@ -91,13 +91,6 @@ static int dwc2_get_dr_mode(struct dwc2_
return 0;
}
-static void __dwc2_disable_regulators(void *data)
-{
- struct dwc2_hsotg *hsotg = data;
-
- regulator_bulk_disable(ARRAY_SIZE(hsotg->supplies), hsotg->supplies);
-}
-
static int __dwc2_lowlevel_hw_enable(struct dwc2_hsotg *hsotg)
{
struct platform_device *pdev = to_platform_device(hsotg->dev);
@@ -108,11 +101,6 @@ static int __dwc2_lowlevel_hw_enable(str
if (ret)
return ret;
- ret = devm_add_action_or_reset(&pdev->dev,
- __dwc2_disable_regulators, hsotg);
- if (ret)
- return ret;
-
if (hsotg->clk) {
ret = clk_prepare_enable(hsotg->clk);
if (ret)
@@ -168,7 +156,7 @@ static int __dwc2_lowlevel_hw_disable(st
if (hsotg->clk)
clk_disable_unprepare(hsotg->clk);
- return 0;
+ return regulator_bulk_disable(ARRAY_SIZE(hsotg->supplies), hsotg->supplies);
}
/**
@@ -607,7 +595,7 @@ error_init:
if (hsotg->params.activate_stm_id_vb_detection)
regulator_disable(hsotg->usb33d);
error:
- if (hsotg->dr_mode != USB_DR_MODE_PERIPHERAL)
+ if (hsotg->ll_hw_enabled)
dwc2_lowlevel_hw_disable(hsotg);
return retval;
}
Patches currently in stable-queue which might be from fabrice.gasnier@xxxxxxxxxxx are
queue-6.2/usb-dwc2-fix-a-race-don-t-power-off-on-phy-for-dual-role-mode.patch
queue-6.2/usb-dwc2-drd-fix-inconsistent-mode-if-role-switch-default-mode-host.patch
queue-6.2/usb-dwc2-fix-a-devres-leak-in-hw_enable-upon-suspend-resume.patch
