Hi, On 18 November 2015 at 15:59, Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote: > On Wed, Nov 18, 2015 at 2:59 AM, Ville Syrjälä > <ville.syrjala@xxxxxxxxxxxxxxx> wrote: >> On Tue, Nov 17, 2015 at 11:43:25AM -0800, Andy Lutomirski wrote: >>> Typing: >>> >>> # cat /sys/devices/pci0000:00/0000:00:02.0/rom >>> >>> Provokes: >>> >>> i915 0000:00:02.0: Invalid ROM contents >> >> Hmm. So there's no PCI option ROM there. I wonder what is there. I >> get the same on my Braswell BTW. I tried to look through the UEFI >> spec a bit, and it seems to say that even for non-legacy option ROMs >> the 0x55aa signature should be there. >> >> But this being the GPU means we may be using the shadow ROM stuff, >> which IIRC assumes that the shadow is at 0xc000. I'm not sure that >> holds anymore with UEFI, and maybe we should be using some UEFI >> trick instead to find out where it actually lives? >> >> BTW what does 'lspci -vv -s 00:02.0' say on your machine? >> > > 00:02.0 VGA compatible controller: Intel Corporation Sky Lake > Integrated Graphics (rev 07) (prog-if 00 [VGA controller]) > DeviceName: Onboard IGD > Subsystem: Dell Device 0704 > Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- > ParErr- Stepping- SERR- FastB2B- DisINTx+ > Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- > <TAbort- <MAbort- >SERR- <PERR- INTx- > Latency: 0 > Interrupt: pin A routed to IRQ 128 > Region 0: Memory at db000000 (64-bit, non-prefetchable) [size=16M] > Region 2: Memory at 90000000 (64-bit, prefetchable) [size=256M] > Region 4: I/O ports at f000 [size=64] > Expansion ROM at <unassigned> [disabled] UEFI has an option to enable option ROMs, which is disabled by default; I wonder if having it disabled prevents all access to the ROM. Mind you, it doesn't seem to be fatal; I've not had any issues with the same machine that I can pin down to lack of ROM. Cheers, Daniel -- 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
