Re: DRMKMS problem on i386 i915 chipset

[rjs%fdy2.co.uk@localhost]

"Mike Pumford" <mpumford%black-star.demon.co.uk@localhost> wrote:
>
> Having a problem getting a 7-BETA KMS kernel to work on my now quite old
> Sony VAIO laptop.
>
> At the point where the console should switch to graphics mode I get a
> load of random colour bars on the screen. The system is still running at
> that point so by typing blind I've been able to gather some debug
> information.
>
> agp0 at pchb0: i915-family chipset
> agp0: detected 7932k stolen memory
> agp0: aperture at 0xc0000000, size 0x10000000
> i915drmkms0 at pci0 dev 2 function 0: vendor 0x8086 product 0x27a2 (rev.
> 0x03)
> drm: Memory usable by graphics device = 256M
> drm: Supports vblank timestamp caching Rev 2 (21.10.2013).
> drm: Driver supports precise vblank timestamp query.
> drm: failed to find VBIOS tables
> i915drmkms0: interrupting at ioapic0 pin 16 (i915)
> drm: GMBUS [i915 gmbus panel] timed out, falling back to bit banging on
> pin 3
> drm: initialized overlay support
> intelfb0 at i915drmkms0
> i915drmkms0: info: registered panic notifier
> intelfb0: framebuffer at 0xdb070000, size 640x480, depth 32, stride 2560
> DRM error in intel_pipe_config_compare: mismatch in
> adjusted_mode.flags(DRM_MODE_FLAG_PHSYNC) (expected 0, found 1)
> warning:
> /work/netbsd/7-stable/src/sys/external/bsd/drm2/dist/drm/i915/intel_display.c:9891:
> pipe state doesn't match!
>
> Making an educated guess I thought that the lack of VBIOS data might be
> triggering the failure to detect the panel so I stuck some debug prints
> in pci_map_rom_md. The code gets as far the call to bus_space_map but
> that call returns an error. I have verified that there appears to be a
> valid VBIOS at 0xc0000 using dd on /dev/mem to dump the first 1MB of
> memory. I can see the string that the VBIOS parser looks for so if the
> bus_space_map() call succeeded I'd probably have a working system.
>
> I guess this code needs to map the memory the same way that /dev/mem
> does to have the BIOS accesses in the DRM code succeed?

Looks like an i2c problem to me, do you get a valid EDID read when
running NetBSD-6 ?

I have an EEEPC that has a similar problem, it sees a NAK from the i2c
bus though not a timeout.

If you can live without DRMKMS I will be adding a 915 driver soon that
will work with non-DRMKMS kernels.

Robert Swindells