[PATCH 6.4 555/800] xhci: Improve the XHCI system resume time

Greg Kroah-Hartman
2023-07-16T20:18:50Z

From: Basavaraj Natikar <Basavaraj.Natikar@amd.com>

[ Upstream commit 1c024241d018cf9fc17aa8d95c3fe77d671d7142 ]

Avoid extra 120ms delay during system resume.

The xHC controller may signal wake up to 120ms before showing which usb
device caused the wake on the xHC port registers.

The xhci driver therefore checks for port activity up to 120ms during
resume, making sure that the hub driver can see the port change, and
won't immediately runtime suspend back due to no port activity.

This is however only needed for runtime resume as system resume will
resume all child hubs and other child usb devices anyway.

Fixes: 253f588c70f6 ("xhci: Improve detection of device initiated wake signal.")
Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
Acked-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20230428140056.1318981-3-Basavaraj.Natikar@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/usb/host/xhci.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 65d54c8a24928..b81313ffeb768 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -1117,7 +1117,7 @@ int xhci_resume(struct xhci_hcd *xhci, pm_message_t msg)
* the first wake signalling failed, give it that chance.
*/
pending_portevent = xhci_pending_portevent(xhci);
- if (!pending_portevent) {
+ if (!pending_portevent && msg.event == PM_EVENT_AUTO_RESUME) {
msleep(120);
pending_portevent = xhci_pending_portevent(xhci);
}
--
2.39.2