This is a note to let you know that I've just added the patch titled usb: dwc3: gadget: Don't modify GEVNTCOUNT in pullup() to the 5.10-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-dwc3-gadget-don-t-modify-gevntcount-in-pullup.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 2f906b6c68e37e4ddb75512dd075cba681655479 Author: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx> Date: Thu Apr 21 19:22:44 2022 -0700 usb: dwc3: gadget: Don't modify GEVNTCOUNT in pullup() [ Upstream commit 8f8034f493b5eb1ad21ff392fd30c0cf9e71f73f ] If the GEVNTCOUNT indicates events in the event buffer, the driver needs to acknowledge them before the controller can halt. Simply let the interrupt handler acknowledges the remaining event generated by the controller while polling for DSTS.DEVCTLHLT. This avoids disabling irq and taking care of race condition between the interrupt handlers and pullup(). Signed-off-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/ea306ec93c41ccafbdb5d16404ff3b6eca299613.1650593829.git.Thinh.Nguyen@xxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Stable-dep-of: 040f2dbd2010 ("usb: dwc3: gadget: Avoid duplicate requests to enable Run/Stop") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index bd1050f75558..818a70e56d89 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -2122,8 +2122,9 @@ static int __dwc3_gadget_start(struct dwc3 *dwc); static int dwc3_gadget_soft_disconnect(struct dwc3 *dwc) { - u32 count; + unsigned long flags; + spin_lock_irqsave(&dwc->lock, flags); dwc->connected = false; /* @@ -2135,29 +2136,21 @@ static int dwc3_gadget_soft_disconnect(struct dwc3 *dwc) */ dwc3_stop_active_transfers(dwc); __dwc3_gadget_stop(dwc); + spin_unlock_irqrestore(&dwc->lock, flags); /* - * In the Synopsys DesignWare Cores USB3 Databook Rev. 3.30a - * Section 1.3.4, it mentions that for the DEVCTRLHLT bit, the - * "software needs to acknowledge the events that are generated - * (by writing to GEVNTCOUNTn) while it is waiting for this bit - * to be set to '1'." + * Note: if the GEVNTCOUNT indicates events in the event buffer, the + * driver needs to acknowledge them before the controller can halt. + * Simply let the interrupt handler acknowledges and handle the + * remaining event generated by the controller while polling for + * DSTS.DEVCTLHLT. */ - count = dwc3_readl(dwc->regs, DWC3_GEVNTCOUNT(0)); - count &= DWC3_GEVNTCOUNT_MASK; - if (count > 0) { - dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), count); - dwc->ev_buf->lpos = (dwc->ev_buf->lpos + count) % - dwc->ev_buf->length; - } - return dwc3_gadget_run_stop(dwc, false, false); } static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on) { struct dwc3 *dwc = gadget_to_dwc(g); - unsigned long flags; int ret; is_on = !!is_on; @@ -2201,14 +2194,6 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on) return 0; } - /* - * Synchronize and disable any further event handling while controller - * is being enabled/disabled. - */ - disable_irq(dwc->irq_gadget); - - spin_lock_irqsave(&dwc->lock, flags); - if (!is_on) { ret = dwc3_gadget_soft_disconnect(dwc); } else { @@ -2218,16 +2203,12 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on) * device-initiated disconnect requires a core soft reset * (DCTL.CSftRst) before enabling the run/stop bit. */ - spin_unlock_irqrestore(&dwc->lock, flags); dwc3_core_soft_reset(dwc); - spin_lock_irqsave(&dwc->lock, flags); dwc3_event_buffers_setup(dwc); __dwc3_gadget_start(dwc); ret = dwc3_gadget_run_stop(dwc, true, false); } - spin_unlock_irqrestore(&dwc->lock, flags); - enable_irq(dwc->irq_gadget); pm_runtime_put(dwc->dev);