Re: [PATCH V2 2/2] efi/fb: Convert PCI bus address to resource if translated by the bridge

[Bartlomiej Zolnierkiewicz]

On Friday, June 22, 2018 09:54:22 AM Ard Biesheuvel wrote:
> On 13 June 2018 at 18:08, Bartlomiej Zolnierkiewicz
> <b.zolnierkie@xxxxxxxxxxx> wrote:
> > On Wednesday, June 13, 2018 05:45:48 PM Ard Biesheuvel wrote:
> >> On 18 May 2018 at 16:17, Sinan Kaya <okaya@xxxxxxxxxxxxxx> wrote:
> >> > A host bridge is allowed to remap BAR addresses using _TRA attribute in
> >> > _CRS windows.
> >> >
> >> > pci_bus 0000:00: root bus resource [mem 0x80100100000-0x8011fffffff window] (bus address [0x00100000-0x1fffffff])
> >> > pci 0000:02:00.0: reg 0x10: [mem 0x8011e000000-0x8011effffff]
> >> >
> >> > When a VGA device is behind such a host bridge and the resource is
> >> > translated efifb driver is trying to do ioremap against bus address
> >> > rather than the resource address and is failing to probe.
> >> >
> >> > efifb: probing for efifb
> >> > efifb: cannot reserve video memory at 0x1e000000
> >> > efifb: framebuffer at 0x1e000000, using 1920k, total 1875k
> >> > efifb: mode is 800x600x32, linelength=3200, pages=1
> >> > efifb: scrolling: redraw
> >> > efifb: Truecolor: size=8:8:8:8, shift=24:16:8:0
> >> >
> >> > Use the host bridge offset information to convert bus address to
> >> > resource address in the fixup.
> >> >
> >> > Signed-off-by: Sinan Kaya <okaya@xxxxxxxxxxxxxx>
> >>
> >> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
> >>
> >> Bartlomiej, could you please take these via the fbdev tree for v4.19?
> >
> > Sure, I will queue it after the current merge window.
> >
> >> Peter already gave his ack but Sinan dropped it (presumably because of
> >> the split in v2)
> >
> > Peter, can I (re)add your ACK to V2 patches?
> >
> 
> Actually, it would be better if we could take this through the EFI
> tree instead, with your ack. Would you mind?

Fine with me.

> There are some other efifb changes coming up, some of which depend on
> core EFI changes, and taking these through different trees is going to
> be more trouble than it's worth.

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics