On Sun, May 01, 2016 at 12:21:05AM +0800, Wang YanQing wrote:
> We can't just break out when meet start is equal to zero,
> this will cause we miss valid address range in later BARs.
>
> On the other hand, it isn't enough to test start only
> for below situation:
> 0(start) <= lfb_base < end
>
> Note: this patch also add a trivial optimization,
> break out after we find the address range
> is valid without test later BARs.
>
> Signed-off-by: Wang YanQing <udkni...@gmail.com>
This looks correct to me:
Reviewed-By: Peter Jones <pjo...@redhat.com>
Cc'ing Matt Fleming, since this should probably go through the EFI tree.
> ---
> Due to the BUG this patch fix, I can't use video=efifb:
> boot parameter to get efifb on my new ThinkPad E550 for
> my old linux system hard disk with 3.10 kernel. In 3.10,
> efifb is the only choice due to DRM/I915 in it doesn't
> support the GPU.
>
> Changes:
> v1-v2:
> 1: Do a trivial code optimization.
>
> arch/x86/kernel/sysfb_efi.c | 14 ++++++++++++--
> 1 file changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kernel/sysfb_efi.c b/arch/x86/kernel/sysfb_efi.c
> index b285d4e..5da924b 100644
> --- a/arch/x86/kernel/sysfb_efi.c
> +++ b/arch/x86/kernel/sysfb_efi.c
> @@ -106,14 +106,24 @@ static int __init efifb_set_system(const struct
> dmi_system_id *id)
> continue;
> for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
> resource_size_t start, end;
> + unsigned long flags;
> +
> + flags = pci_resource_flags(dev, i);
> + if (!(flags & IORESOURCE_MEM))
> + continue;
> +
> + if (flags & IORESOURCE_UNSET)
> + continue;
> +
> + if (pci_resource_len(dev, i) == 0)
> + continue;
>
> start = pci_resource_start(dev, i);
> - if (start == 0)
> - break;
> end = pci_resource_end(dev, i);
> if (screen_info.lfb_base >= start &&
> screen_info.lfb_base < end) {
> found_bar = 1;
> + break;
> }
> }
> }
> --
> 1.8.5.6.2.g3d8a54e.dirty
--
Peter
