[v2] usb: dwc3: Prevent indefinite sleep in _dwc3_set_mode during suspend/resume
From: Roger Quadros <hidden>
Date: 2018-03-16 10:34:15
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Hi Felipe, On 09/03/18 14:47, Roger Quadros wrote:
In the following test we get stuck by sleeping forever in _dwc3_set_mode() after which dual-role switching doesn't work. On dra7-evm's dual-role port, - Load g_zero gadget driver and enumerate to host - suspend to mem - disconnect USB cable to host and connect otg cable with Pen drive in it. - resume system - we sleep indefinitely in _dwc3_set_mode due to. dwc3_gadget_exit()->usb_del_gadget_udc()->udc_stop()-> dwc3_gadget_stop()->wait_event_lock_irq() To fix this instead of waiting indefinitely with wait_event_lock_irq() we use wait_event_interruptible_lock_irq_timeout() and print and error message if there was a timeout. Signed-off-by: Roger Quadros <redacted>
Thanks for picking this for -next. Is it better to have this in v4.16-rc fixes? and also stable? v4.12+
quoted hunk ↗ jump to hunk
--- Changelog: v2: - use wait_event_interruptible_lock_irq_timeout() instead of wait_event_lock_irq() drivers/usb/dwc3/gadget.c | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-)diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 2bda4eb..7c3a6e4 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c@@ -1950,6 +1950,7 @@ static int dwc3_gadget_stop(struct usb_gadget *g) struct dwc3 *dwc = gadget_to_dwc(g); unsigned long flags; int epnum; + u32 tmo_eps = 0; spin_lock_irqsave(&dwc->lock, flags);@@ -1960,6 +1961,7 @@ static int dwc3_gadget_stop(struct usb_gadget *g) for (epnum = 2; epnum < DWC3_ENDPOINTS_NUM; epnum++) { struct dwc3_ep *dep = dwc->eps[epnum]; + int ret; if (!dep) continue;@@ -1967,9 +1969,24 @@ static int dwc3_gadget_stop(struct usb_gadget *g) if (!(dep->flags & DWC3_EP_END_TRANSFER_PENDING)) continue; - wait_event_lock_irq(dep->wait_end_transfer, - !(dep->flags & DWC3_EP_END_TRANSFER_PENDING), - dwc->lock); + ret = wait_event_interruptible_lock_irq_timeout(dep->wait_end_transfer, + !(dep->flags & DWC3_EP_END_TRANSFER_PENDING), + dwc->lock, msecs_to_jiffies(5)); + + if (ret <= 0) { + /* Timed out or interrupted! There's nothing much + * we can do so we just log here and print which + * endpoints timed out at the end. + */ + tmo_eps |= 1 << epnum; + dep->flags &= DWC3_EP_END_TRANSFER_PENDING; + } + } + + if (tmo_eps) { + dev_err(dwc->dev, + "end transfer timed out on endpoints 0x%x [bitmap]\n", + tmo_eps); } out: