> > [+cc Bjørn] > > On Tue, Nov 12, 2013 at 10:39 PM, wzyboy <wzyboy@xxxxxxxxxx> wrote: > > 2013/11/13 Bjorn Helgaas <bhelgaas@xxxxxxxxxx>: > >> wzyboy, can you run these commands before the bug occurs and before > >> using the "setpci" workaround: > >> > >> lspci -vvxxxx -s00:1c.1 > >> lspci -vvxxxx -s03:00.0 > > > > After today's morning lessons I booted up my laptop with pci=earlydump > > kernel perameter and here are the output of lspci (without setpci and > > before bug hit) and dmesg. > > Thanks. Are you 100% sure the lspci output is before the setpci workaround? > The dmesg earlydump shows this (the ASPM control bits are in the 16-bit Link > Control register, which is at 0x50 for both > devices): > > 00:1c.1 Root Port config > 50: 42 00 11 70 00 b2 14 00 00 00 40 01 00 00 00 00 > 03:00.0 Intel 7260 config: > 50: 42 01 11 10 00 00 00 00 00 00 00 00 00 00 00 00 > > So at boot-time, ASPM was enabled. But the lspci shows: > > 00:1c.1 Root Port config > Capabilities: [40] Express (v2) Root Port (Slot+), MSI 00 > LnkCtl: ASPM Disabled > 50: 40 00 11 70 00 b2 14 00 00 00 40 01 00 00 00 00 > 03:00.0 Intel 7620 config > Capabilities: [40] Express (v2) Endpoint, MSI 00 > LnkCtl: ASPM Disabled > 50: 40 01 11 10 00 00 00 00 00 00 00 00 00 00 00 00 > > And now ASPM is disabled. I'm pretty sure the kernel did not disable ASPM, > so I assume it was disabled by setpci. > > I manually decoded the L1 PM Substates registers for both the Root Port and > the 7260 device (details appended below), and everything appears enabled > there (though I think that since ASPM is disabled, L1 PM substates is > ignored). > > My conclusion is that the BIOS enabled both ASPM and L1 PM substates. > Obviously the BIOS will do the same when booting Windows, and I assume > the device works fine with the Windows driver. Based on our previous > experience with Windows, I don't think it will change the ASPM configuration > because the ACPI FADT table and the PCI _OSC method do not grant control > of ASPM to the OS. Therefore, I think the problem is in the Linux iwlwifi > driver. > > I don't think there's anything more I can do here because there's no > evidence that the PCI core is doing anything wrong. But if it turns out that we > *should* be doing something differently, let me know. > Right - no evidence of anything - Thank you a lot for all your help. I have learnt a lot from this thread. I guess I'll try to disable L1 PM substates with setpci command and see what happens. > Bjorn > > > 00:1c.1 Root Port config > Capabilities: [40] Express (v2) Root Port (Slot+), MSI 00 > LnkCtl: ASPM Disabled > 50: 40 00 11 70 00 b2 14 00 00 00 40 01 00 00 00 00 > Capabilities: [200 v1] #1e > 200: 1e 00 01 00 1f 28 28 00 1f 28 a0 40 f0 00 00 00 > 210: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > Header 0x0001001e > ID 0x001e (L1 Substates) > Version 1 > Capabilities 0x0028281f > Control 1 0x40a0281f > 0x40a0281f Control 1 > 0x00000001 PCI-PM L1.2 Enable > 0x00000002 PCI-PM L1.1 Enable > 0x00000004 ASPM L1.2 Enable > 0x00000008 ASPM L1.1 Enable > 0x00000010 RsvdP > 0x00002800 Common_Mode_Restore_Time > 0x00a00000 LTR_L1.2_THRESHOLD_Value > 0x40000000 LTR_L1.2_THRESHOLD_Scale > Control 2 0x000000f0 > 0x000000f0 Control 2 > 0x000000f0 T_POWER_ON Value > > 03:00.0 Intel 7620 config > Capabilities: [40] Express (v2) Endpoint, MSI 00 > LnkCtl: ASPM Disabled > 50: 40 01 11 10 00 00 00 00 00 00 00 00 00 00 00 00 > Capabilities: [154 v1] Vendor Specific Information: ID=cafe > Rev=1 Len=014 <?> > 150: 0b 00 01 00 fe ca 41 01 1f 1e f0 00 > 160: 0f 00 a0 40 f0 00 00 00 00 00 00 00 00 00 00 00 > Header 0x0001000b > ID 0x000b (Vendor-specific) > Version 1 > Vendor-specific header 0x0141cafe > VSEC ID 0xcafe > VSEC Rev 1 > Length 0x14 > Capabilities 0x00f01e1f > Control 1 0x40a0000f > 0x40a0000f Control 1 > 0x00000001 PCI-PM L1.2 Enable > 0x00000002 PCI-PM L1.1 Enable > 0x00000004 ASPM L1.2 Enable > 0x00000008 ASPM L1.1 Enable > Control 2 0x000000f0 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
