Manyi, FYI, your emails aren't making it to the linux-pci list (or to me), so I'm missing most of this conversation. If you look at the lore archive: https://lore.kernel.org/all/20220713112612.6935-1-limanyi@xxxxxxxxxxxxx/ you'll see all the message-ids that are not found. Maybe you're sending HTML or something else vger doesn't like? http://vger.kernel.org/majordomo-info.html#taboo On Fri, Jul 15, 2022 at 10:32:36AM +0100, Matthew Garrett wrote: > On Fri, Jul 15, 2022 at 05:19:25PM +0800, Manyi Li wrote: > > On 2022/7/15 16:29, Matthew Garrett wrote: > > > On Fri, Jul 15, 2022 at 03:40:36PM +0800, Manyi Li wrote: > > > > > > > Please see the details of this issus: > > > > https://bugzilla.kernel.org/show_bug.cgi?id=216245 > > > > > > Hmm. The only case where changing aspm_support_enabled to false should > > > matter is in pcie_aspm_init_link_state(), where it looks like we'll > > > potentially rewrite some registers even if aspm_disabled is true. I > > > think in theory we shouldn't actually modify anything as a result, and > > > the lspcis from the bug don't show any ASPM values having changed, but I > > > don't trust Realtek hardware in the general case so maybe it gets upset > > > here? If the proposed patch is to just set aspm_support_enabled to false > > > when we see the FADT bit set then I think this is fine. > > > > > > > "aspm_support_enabled" alse be used in calculate_support(): > > if (pcie_aspm_support_enabled()) > > support |= OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT; > > When set OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT, cause this AER > > issue. I want don't set OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT when > > we see the FADT bit set. > > Oh hm. Are you sure it's the OSC call that breaks it? I have some > recollection that I verified the behaviour of Windows here, but it's > been over 10 years since I touched this so I could well be wrong. I can > try to set up a test env to verify the behaviour of Windows when it > comes to _OSC if the FADT says ASPM is unsupported.
