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SubjectRe: [PATCH] efi/fb: Convert PCI bus address to resource if translated by the bridge
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@codeaurora.org>

Looks reasonable to me - Ard, do you want to take this up through the
EFI tree?

Signed-off-by: Peter Jones <pjones@redhat.com>

> ---
> 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, &region);
> + 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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