From: Fabrice Gasnier fabrice.gasnier@foss.st.com
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@kernel.org Signed-off-by: Fabrice Gasnier fabrice.gasnier@foss.st.com Link: https://lore.kernel.org/r/20230316084127.126084-1-fabrice.gasnier@foss.st.co... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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; }