On Thu, Apr 24, 2025 at 12:59:55PM +0200, Rafael J. Wysocki wrote: > On Thu, Apr 24, 2025 at 7:12 AM Raag Jadav <raag.jadav@xxxxxxxxx> wrote: > > > > On Tue, Apr 22, 2025 at 02:45:37PM -0500, Bjorn Helgaas wrote: > > > On Tue, Apr 22, 2025 at 07:23:41PM +0530, Raag Jadav wrote: > > > > If an error is triggered before or during system suspend, any bus level > > > > power state transition will result in unpredictable behaviour by the > > > > device with failed recovery. Avoid suspending such a device and leave > > > > it in its existing power state. > > > > > > > > This only covers the devices that rely on PCI core PM for their power > > > > state transition. > > > > > > > > Signed-off-by: Raag Jadav <raag.jadav@xxxxxxxxx> > > > > --- > > > > > > > > v2: Synchronize AER handling with PCI PM (Rafael) > > > > > > > > More discussion on [1]. > > > > [1] https://lore.kernel.org/all/CAJZ5v0g-aJXfVH+Uc=9eRPuW08t-6PwzdyMXsC6FZRKYJtY03Q@xxxxxxxxxxxxxx/ > > > > > > Thanks for the pointer, but the commit log for this patch needs to be > > > complete in itself. "Unpredictable behavior" is kind of hand-wavy and > > > doesn't really help understand the problem. > > > > > > > drivers/pci/pci-driver.c | 3 ++- > > > > drivers/pci/pcie/aer.c | 11 +++++++++++ > > > > include/linux/aer.h | 2 ++ > > > > 3 files changed, 15 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c > > > > index f57ea36d125d..289a1fa7cb2d 100644 > > > > --- a/drivers/pci/pci-driver.c > > > > +++ b/drivers/pci/pci-driver.c > > > > @@ -884,7 +884,8 @@ static int pci_pm_suspend_noirq(struct device *dev) > > > > } > > > > } > > > > > > > > - if (!pci_dev->state_saved) { > > > > + /* Avoid suspending the device with errors */ > > > > + if (!pci_aer_in_progress(pci_dev) && !pci_dev->state_saved) { > > > > > > This looks potentially racy, since hardware can set bits in > > > PCI_EXP_DEVSTA at any time. > > > > Which is why it's placed in ->suspend_noirq() callback. Can it still race? > > With the hardware? Yes. Any thoughts on potential side effects and how to address them? Raag
