Messages in this thread | | | Date | Wed, 13 Jun 2018 11:50:19 -0400 | From | okaya@codeauro ... | Subject | Re: [PATCH V2 2/2] efi/fb: Convert PCI bus address to resource if translated by the bridge |
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On 2018-06-13 11:45, Ard Biesheuvel wrote: > On 18 May 2018 at 16:17, Sinan Kaya <okaya@codeaurora.org> 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@codeaurora.org> > > Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > > Bartlomiej, could you please take these via the fbdev tree for v4.19? > Peter already gave his ack but Sinan dropped it (presumably because of > the split in v2) > > Sinan, does this need to go to -stable? I.e., has it ever worked > before? >
Yes, it needs to go to stable. It never worked before. Issue was found during a graphics bring up with AST driver.
It needs a 32 bit graphics card and a 32 bit translating host bridge to hit the issue.
> > >> --- >> 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, >> .flags = IORESOURCE_MEM, >> }; >> + 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) >> return; >> >> + region.start = screen_res.start; >> + region.end = screen_res.end; >> + pcibios_bus_to_resource(dev->bus, &screen_res, ®ion); >> + >> for (i = 0; i <= PCI_STD_RESOURCE_END; i++) { >> struct resource *res = &dev->resource[i]; >> >> -- >> 2.7.4 >> >> >> _______________________________________________ >> linux-arm-kernel mailing list >> linux-arm-kernel@lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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