Messages in this thread | | | From | "Rafael J. Wysocki" <> | Date | Mon, 24 Jun 2019 23:37:29 +0200 | Subject | Re: [PATCH v2] PCI: PM: Skip devices in D0 for suspend-to-idle |
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On Mon, Jun 24, 2019 at 2:43 PM Jon Hunter <jonathanh@nvidia.com> wrote: > > Hi Rafael, > > On 13/06/2019 22:59, Rafael J. Wysocki wrote: > > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > > > Commit d491f2b75237 ("PCI: PM: Avoid possible suspend-to-idle issue") > > attempted to avoid a problem with devices whose drivers want them to > > stay in D0 over suspend-to-idle and resume, but it did not go as far > > as it should with that. > > > > Namely, first of all, the power state of a PCI bridge with a > > downstream device in D0 must be D0 (based on the PCI PM spec r1.2, > > sec 6, table 6-1, if the bridge is not in D0, there can be no PCI > > transactions on its secondary bus), but that is not actively enforced > > during system-wide PM transitions, so use the skip_bus_pm flag > > introduced by commit d491f2b75237 for that. > > > > Second, the configuration of devices left in D0 (whatever the reason) > > during suspend-to-idle need not be changed and attempting to put them > > into D0 again by force is pointless, so explicitly avoid doing that. > > > > Fixes: d491f2b75237 ("PCI: PM: Avoid possible suspend-to-idle issue") > > Reported-by: Kai-Heng Feng <kai.heng.feng@canonical.com> > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> > > Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com> > > I have noticed a regression in both the mainline and -next branches on > one of our boards when testing suspend. The bisect is point to this > commit and reverting on top of mainline does fix the problem. So far I > have not looked at this in close detail but kernel log is showing ...
Can you please collect a log like that, but with dynamic debug in pci-driver.c enabled?
Note that reverting this commit is rather out of the question, so we need to get to the bottom of the failure.
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