diff options
| author |   Thinh Nguyen <Thinh.Nguyen@synopsys.com> | 2022-06-27 18:41:19 -0700 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-06-29 21:04:54 +0200 |
| commit | 7441b273388b9a59d8387a03ffbbca9d5af6348c (patch) | |
| tree | 4b2b8f75d184aae824e5855a6389d1ac6565ea47 /drivers/usb/dwc3/gadget.c | |
| parent | Linux 5.19-rc4 (diff) | |
| download | linux-dev-7441b273388b9a59d8387a03ffbbca9d5af6348c.tar.xz linux-dev-7441b273388b9a59d8387a03ffbbca9d5af6348c.zip | |
usb: dwc3: gadget: Fix event pending check
The DWC3_EVENT_PENDING flag is used to protect against invalid call to
top-half interrupt handler, which can occur when there's a delay in
software detection of the interrupt line deassertion.
However, the clearing of this flag was done prior to unmasking the
interrupt line, creating opportunity where the top-half handler can
come. This breaks the serialization and creates a race between the
top-half and bottom-half handler, resulting in losing synchronization
between the controller and the driver when processing events.
To fix this, make sure the clearing of the DWC3_EVENT_PENDING is done at
the end of the bottom-half handler.
Fixes: d325a1de49d6 ("usb: dwc3: gadget: Prevent losing events in event cache")
Cc: stable@vger.kernel.org
Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/8670aaf1cf52e7d1e6df2a827af2d77263b93b75.1656380429.git.Thinh.Nguyen@synopsys.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/dwc3/gadget.c')
| -rw-r--r-- | drivers/usb/dwc3/gadget.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 8716bece1072..0d89dfa6eef5 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -4249,7 +4249,6 @@ static irqreturn_t dwc3_process_event_buf(struct dwc3_event_buffer *evt) } evt->count = 0; - evt->flags &= ~DWC3_EVENT_PENDING; ret = IRQ_HANDLED; /* Unmask interrupt */ @@ -4261,6 +4260,9 @@ static irqreturn_t dwc3_process_event_buf(struct dwc3_event_buffer *evt) dwc3_writel(dwc->regs, DWC3_DEV_IMOD(0), dwc->imod_interval); } + /* Keep the clearing of DWC3_EVENT_PENDING at the end */ + evt->flags &= ~DWC3_EVENT_PENDING; + return ret; } |