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List:       linux-usb
Subject:    [PATCH v4 2/2] xhci: Improve the XHCI system resume time
From:       Basavaraj Natikar <Basavaraj.Natikar () amd ! com>
Date:       2023-04-28 14:12:56
Message-ID: 20230428140056.1318981-3-Basavaraj.Natikar () amd ! com
[Download RAW message or body]

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>
---
 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 11a87b9cbb50..4c0a2b9ca7b2 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -1315,7 +1315,7 @@ 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);
 		}
-- 
2.25.1

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