From ad4505a13725e0af88ad868c37b4ab34d6d3dde3 Mon Sep 17 00:00:00 2001 From: Bjorn Andersson Date: Sat, 15 May 2021 21:09:53 -0700 Subject: [PATCH] usb: typec: ucsi: Clear pending after acking connector change commit 8c9b3caab3ac26db1da00b8117901640c55a69dd upstream. It's possible that the interrupt handler for the UCSI driver signals a connector changes after the handler clears the PENDING bit, but before it has sent the acknowledge request. The result is that the handler is invoked yet again, to ack the same connector change. At least some versions of the Qualcomm UCSI firmware will not handle the second - "spurious" - acknowledgment gracefully. So make sure to not clear the pending flag until the change is acknowledged. Any connector changes coming in after the acknowledgment, that would have the pending flag incorrectly cleared, would afaict be covered by the subsequent connector status check. Fixes: 217504a05532 ("usb: typec: ucsi: Work around PPM losing change information") Cc: stable Reviewed-by: Heikki Krogerus Acked-By: Benjamin Berg Signed-off-by: Bjorn Andersson Link: https://lore.kernel.org/r/20210516040953.622409-1-bjorn.andersson@linaro.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman --- drivers/usb/typec/ucsi/ucsi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c index 1e266f083bf8a..7104ddb9696d6 100644 --- a/drivers/usb/typec/ucsi/ucsi.c +++ b/drivers/usb/typec/ucsi/ucsi.c @@ -717,8 +717,8 @@ static void ucsi_handle_connector_change(struct work_struct *work) ucsi_send_command(con->ucsi, command, NULL, 0); /* 3. ACK connector change */ - clear_bit(EVENT_PENDING, &ucsi->flags); ret = ucsi_acknowledge_connector_change(ucsi); + clear_bit(EVENT_PENDING, &ucsi->flags); if (ret) { dev_err(ucsi->dev, "%s: ACK failed (%d)", __func__, ret); goto out_unlock;