[PATCH 4.9 44/92] xhci: Check all endpoints for LPM timeout

From: Greg Kroah-Hartman
Date: Wed Oct 16 2019 - 18:17:19 EST

From: Jan Schmidt <jan@xxxxxxxxxxxxxxx>

commit d500c63f80f2ea08ee300e57da5f2af1c13875f5 upstream.

If an endpoint is encountered that returns USB3_LPM_DEVICE_INITIATED, keep
checking further endpoints, as there might be periodic endpoints later
that return USB3_LPM_DISABLED due to shorter service intervals.

Without this, the code can set too high a maximum-exit-latency and
prevent the use of multiple USB3 cameras that should be able to work.

Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Jan Schmidt <jan@xxxxxxxxxxxxxxx>
Tested-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/1570190373-30684-4-git-send-email-mathias.nyman@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

drivers/usb/host/xhci.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -4510,12 +4510,12 @@ static int xhci_update_timeout_for_endpo
alt_timeout = xhci_call_host_update_timeout_for_endpoint(xhci, udev,
desc, state, timeout);

- /* If we found we can't enable hub-initiated LPM, or
+ /* If we found we can't enable hub-initiated LPM, and
* the U1 or U2 exit latency was too high to allow
- * device-initiated LPM as well, just stop searching.
+ * device-initiated LPM as well, then we will disable LPM
+ * for this device, so stop searching any further.
- if (alt_timeout == USB3_LPM_DISABLED ||
- alt_timeout == USB3_LPM_DEVICE_INITIATED) {
+ if (alt_timeout == USB3_LPM_DISABLED) {
*timeout = alt_timeout;
return -E2BIG;