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Subject[PATCH V2 2/2] efi/fb: Convert PCI bus address to resource if translated by the bridge
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 <>
drivers/video/fbdev/efifb.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/video/fbdev/efifb.c b/drivers/video/fbdev/efifb.c
index 6daac8d..429cc85 100644
--- a/drivers/video/fbdev/efifb.c
+++ b/drivers/video/fbdev/efifb.c
@@ -431,6 +431,7 @@ static void efifb_fixup_resources(struct pci_dev *dev)
.end = screen_info.lfb_base + screen_info.lfb_size - 1,
+ struct pci_bus_region region;
int i;

if (efifb_pci_dev || screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)
@@ -442,6 +443,10 @@ static void efifb_fixup_resources(struct pci_dev *dev)
if (!screen_res.start)

+ region.start = screen_res.start;
+ region.end = screen_res.end;
+ pcibios_bus_to_resource(dev->bus, &screen_res, &region);
for (i = 0; i <= PCI_STD_RESOURCE_END; i++) {
struct resource *res = &dev->resource[i];

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