On 17 May 2018 at 16:55, Peter Jones <pjones@xxxxxxxxxx> wrote:
> On Thu, May 17, 2018 at 09:22:23AM -0400, Sinan Kaya 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 driver is having difficulty locating the base address from BAR
>> address when
>>
>> 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>
>
> Looks reasonable to me - Ard, do you want to take this up through the
> EFI tree?
>
Sure
> Signed-off-by: Peter Jones <pjones@xxxxxxxxxx>
>
I'll take that as a reviewed-by, thanks.
>> ---
>> drivers/video/fbdev/efifb.c | 10 ++++++++++
>> 1 file changed, 10 insertions(+)
>>
>> diff --git a/drivers/video/fbdev/efifb.c b/drivers/video/fbdev/efifb.c
>> index 46a4484..ea68d5c 100644
>> --- a/drivers/video/fbdev/efifb.c
>> +++ b/drivers/video/fbdev/efifb.c
>> @@ -428,6 +428,8 @@ static void efifb_fixup_resources(struct pci_dev *dev)
>> {
>> u64 base = screen_info.lfb_base;
>> u64 size = screen_info.lfb_size;
>> + struct pci_bus_region region;
>> + struct resource res;
>> int i;
>>
>> if (efifb_pci_dev || screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)
>> @@ -439,6 +441,14 @@ static void efifb_fixup_resources(struct pci_dev *dev)
>> if (!base)
>> return;
>>
>> + region.start = base;
>> + region.end = base + size - 1;
>> + res.start = 0;
>> + res.flags = IORESOURCE_MEM;
>> + pcibios_bus_to_resource(dev->bus, &res, ®ion);
>> + if (res.start)
>> + base = res.start;
>> +
>> for (i = 0; i <= PCI_STD_RESOURCE_END; i++) {
>> struct resource *res = &dev->resource[i];
>>
>> --
>> 2.7.4
>>
>
> --
> Peter
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