This is a note to let you know that I've just added the patch titled
usb: dwc3: gadget: Avoid runtime resume if disabling pullup
to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
From cb10f68ad8150f243964b19391711aaac5e8ff42 Mon Sep 17 00:00:00 2001
From: Wesley Cheng wcheng@codeaurora.org Date: Tue, 3 Aug 2021 23:24:05 -0700 Subject: usb: dwc3: gadget: Avoid runtime resume if disabling pullup
If the device is already in the runtime suspended state, any call to the pullup routine will issue a runtime resume on the DWC3 core device. If the USB gadget is disabling the pullup, then avoid having to issue a runtime resume, as DWC3 gadget has already been halted/stopped.
This fixes an issue where the following condition occurs:
usb_gadget_remove_driver() -->usb_gadget_disconnect() -->dwc3_gadget_pullup(0) -->pm_runtime_get_sync() -> ret = 0 -->pm_runtime_put() [async] -->usb_gadget_udc_stop() -->dwc3_gadget_stop() -->dwc->gadget_driver = NULL ...
dwc3_suspend_common() -->dwc3_gadget_suspend() -->DWC3 halt/stop routine skipped, driver_data == NULL
This leads to a situation where the DWC3 gadget is not properly stopped, as the runtime resume would have re-enabled EP0 and event interrupts, and since we avoided the DWC3 gadget suspend, these resources were never disabled.
Fixes: 77adb8bdf422 ("usb: dwc3: gadget: Allow runtime suspend if UDC unbinded") Cc: stable stable@vger.kernel.org Acked-by: Felipe Balbi balbi@kernel.org Signed-off-by: Wesley Cheng wcheng@codeaurora.org Link: https://lore.kernel.org/r/1628058245-30692-1-git-send-email-wcheng@codeauror... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/dwc3/gadget.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index a1b262669574..b8d4b2d327b2 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -2256,6 +2256,17 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on) } }
+ /* + * Avoid issuing a runtime resume if the device is already in the + * suspended state during gadget disconnect. DWC3 gadget was already + * halted/stopped during runtime suspend. + */ + if (!is_on) { + pm_runtime_barrier(dwc->dev); + if (pm_runtime_suspended(dwc->dev)) + return 0; + } + /* * Check the return value for successful resume, or error. For a * successful resume, the DWC3 runtime PM resume routine will handle