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* [PATCH] PCI/PM: Skip link training delay for S3 resume
@ 2020-03-11  4:52 Kai-Heng Feng
  2020-03-11 10:28 ` Mika Westerberg
  0 siblings, 1 reply; 6+ messages in thread
From: Kai-Heng Feng @ 2020-03-11  4:52 UTC (permalink / raw)
  To: bhelgaas; +Cc: mika.westerberg, linux-pci, linux-kernel, Kai-Heng Feng

Commit ad9001f2f411 ("PCI/PM: Add missing link delays required by the
PCIe spec") added a 1100ms delay on resume for bridges that don't
support Link Active Reporting.

The commit also states that the delay can be skipped for S3, as the
firmware should already handled the case for us.

So let's skip the link training delay for S3, to save 1100ms resume
time.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
 drivers/pci/pci-driver.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index 0454ca0e4e3f..3050375bad04 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -916,7 +916,8 @@ static int pci_pm_resume_noirq(struct device *dev)
 	pci_fixup_device(pci_fixup_resume_early, pci_dev);
 	pcie_pme_root_status_cleanup(pci_dev);
 
-	if (!skip_bus_pm && prev_state == PCI_D3cold)
+	if (!skip_bus_pm && prev_state == PCI_D3cold
+	    && !pm_resume_via_firmware())
 		pci_bridge_wait_for_secondary_bus(pci_dev);
 
 	if (pci_has_legacy_pm_support(pci_dev))
-- 
2.17.1


^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2020-03-12 10:08 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-03-11  4:52 [PATCH] PCI/PM: Skip link training delay for S3 resume Kai-Heng Feng
2020-03-11 10:28 ` Mika Westerberg
2020-03-12  4:23   ` Kai-Heng Feng
2020-03-12  8:04     ` Mika Westerberg
2020-03-12  9:45       ` Kai-Heng Feng
2020-03-12 10:08         ` Mika Westerberg

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