[PATCH AUTOSEL 5.4 21/57] usb: gadget: udc: atmel: Fix vbus disconnect handling

From: Sasha Levin
Date: Thu Apr 30 2020 - 10:07:16 EST


From: Cristian Birsan <cristian.birsan@xxxxxxxxxxxxx>

[ Upstream commit 12b94da411f9c6d950beb067d913024fd5617a61 ]

A DMA transfer can be in progress while vbus is lost due to a cable
disconnect. For endpoints that use DMA, this condition can lead to
peripheral hang. The patch ensures that endpoints are disabled before
the clocks are stopped to prevent this issue.

Fixes: a64ef71ddc13 ("usb: gadget: atmel_usba_udc: condition clocks to vbus state")
Signed-off-by: Cristian Birsan <cristian.birsan@xxxxxxxxxxxxx>
Signed-off-by: Felipe Balbi <balbi@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/usb/gadget/udc/atmel_usba_udc.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.c b/drivers/usb/gadget/udc/atmel_usba_udc.c
index 1d0d8952a74bf..58e5b015d40e6 100644
--- a/drivers/usb/gadget/udc/atmel_usba_udc.c
+++ b/drivers/usb/gadget/udc/atmel_usba_udc.c
@@ -1950,10 +1950,10 @@ static irqreturn_t usba_vbus_irq_thread(int irq, void *devid)
usba_start(udc);
} else {
udc->suspended = false;
- usba_stop(udc);
-
if (udc->driver->disconnect)
udc->driver->disconnect(&udc->gadget);
+
+ usba_stop(udc);
}
udc->vbus_prev = vbus;
}
--
2.20.1