From: Wang YanQing <[email protected]> We can't just break out when meet start is equal to zero, this will cause us to miss valid address ranges in later BARs.
On the other hand, it isn't enough to test start only for below situation: 0(start) <= lfb_base < end 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. 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 <[email protected]> Reviewed-by: Peter Jones <[email protected]> Cc: David Herrmann <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Tomi Valkeinen <[email protected]> Cc: <[email protected]> [ Updated changelog ] Signed-off-by: Matt Fleming <[email protected]> --- 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 b285d4e8c68e..5da924bbf0a0 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; } } } -- 2.7.3
