On Friday, June 22, 2018 09:54:22 AM Ard Biesheuvel wrote:

On 13 June 2018 at 18:08, Bartlomiej Zolnierkiewicz
[off-list ref] wrote:

quoted

On Wednesday, June 13, 2018 05:45:48 PM Ard Biesheuvel wrote:

quoted

On 18 May 2018 at 16:17, Sinan Kaya [off-list ref] wrote:

quoted

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, linelength200, pages=1
efifb: scrolling: redraw
efifb: Truecolor: size=8:8:8:8, shift$:16:8:0

Use the host bridge offset information to convert bus address to
resource address in the fixup.

Signed-off-by: Sinan Kaya <redacted>

Reviewed-by: Ard Biesheuvel <redacted>

Bartlomiej, could you please take these via the fbdev tree for v4.19?

Sure, I will queue it after the current merge window.

quoted

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