Re: [Bug 216877] New: Regression in PCI powermanagement breaks resume after suspend

From: Thomas Witt
Date: Thu Jan 26 2023 - 14:25:12 EST


On 04/01/2023 16:37, Thomas Witt wrote:
On 04/01/2023 16:02, Bjorn Helgaas wrote:
Thanks for testing it.  Maybe Vidya will have more ideas.  The patch
below (based on v6.2-rc1) would revert 5e85eba6f50d and 4ff116d0d5fd.
If 5e85eba6f50d is the culprit, it should fix the regression.  It
would also potentially break L1 substates after resume, so we'd like
to avoid reverting it if possible.

But the "Unable to change power state from D3hot to D0, device
inaccessible" symptom suggests that the device is still in D3, which
would be more like a wakeup issue than an ASPM issue.

Your bisect log said 3e347969a577 ("PCI/PM: Reduce D3hot delay with
usleep_range()") was "good", but it would be worth double-checking,
e.g., see if reverting it from v6.2-rc1 makes any difference.

Bjorn

commit 61de2691d549 ("Revert "PCI/ASPM: Refactor L1 PM Substates Control Register programming"")
parent 1b929c02afd3
Author: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Date:   Wed Jan 4 08:38:53 2023 -0600

     Revert "PCI/ASPM: Refactor L1 PM Substates Control Register programming"

With this patch on top of 6.2-rc1 suspend/resume works and my PCI devices come back online.


Hello Bjorn, hello Vidya,

do you have an Idea what went wrong in that commit to cause my PCI devices to not return from D3?

BR
Thomas