From: Pierre Asselin pa@panix.com
[ Upstream commit 1b617bc93178912fa36f87a957c15d1f1708c299 ]
Some legacy BIOSes report no reserved bits in their 32-bit rgb mode, breaking the calculation of bits_per_pixel in commit f35cd3fa7729 ("firmware/sysfb: Fix EFI/VESA format selection"). However they report lfb_depth correctly for those modes. Keep the computation but set bits_per_pixel to lfb_depth if the latter is larger.
v2 fixes the warnings from a max3() macro with arguments of different types; split the bits_per_pixel assignment to avoid uglyfing the code with too many typecasts.
v3 fixes space and formatting blips pointed out by Javier, and change the bit_per_pixel assignment back to a single statement using two casts.
v4 go back to v2 and use max_t()
Signed-off-by: Pierre Asselin pa@panix.com Fixes: f35cd3fa7729 ("firmware/sysfb: Fix EFI/VESA format selection") Link: https://lore.kernel.org/r/4Psm6B6Lqkz1QXM@panix3.panix.com Link: https://lore.kernel.org/r/20230412150225.3757223-1-javierm@redhat.com Tested-by: Thomas Zimmermann tzimmermann@suse.de Signed-off-by: Thomas Zimmermann tzimmermann@suse.de Link: https://patchwork.freedesktop.org/patch/msgid/20230419044834.10816-1-pa@pani... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/firmware/sysfb_simplefb.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/firmware/sysfb_simplefb.c b/drivers/firmware/sysfb_simplefb.c index 82c64cb9f5316..74363ed7501f6 100644 --- a/drivers/firmware/sysfb_simplefb.c +++ b/drivers/firmware/sysfb_simplefb.c @@ -51,7 +51,8 @@ __init bool sysfb_parse_mode(const struct screen_info *si, * * It's not easily possible to fix this in struct screen_info, * as this could break UAPI. The best solution is to compute - * bits_per_pixel here and ignore lfb_depth. In the loop below, + * bits_per_pixel from the color bits, reserved bits and + * reported lfb_depth, whichever is highest. In the loop below, * ignore simplefb formats with alpha bits, as EFI and VESA * don't specify alpha channels. */ @@ -60,6 +61,7 @@ __init bool sysfb_parse_mode(const struct screen_info *si, si->green_size + si->green_pos, si->blue_size + si->blue_pos), si->rsvd_size + si->rsvd_pos); + bits_per_pixel = max_t(u32, bits_per_pixel, si->lfb_depth); } else { bits_per_pixel = si->lfb_depth; }