diff options
| author | Pierre Asselin <pa@panix.com> | 2023-04-19 06:48:34 +0200 |
|---|---|---|
| committer | Thomas Zimmermann <tzimmermann@suse.de> | 2023-04-21 14:27:31 +0200 |
| commit | 1b617bc93178912fa36f87a957c15d1f1708c299 (patch) | |
| tree | 60d30fa12b316ac456d883b31088e87da53b12b7 /drivers | |
| parent | drm/fbdev-generic: prohibit potential out-of-bounds access (diff) | |
| download | linux-1b617bc93178912fa36f87a957c15d1f1708c299.tar.xz linux-1b617bc93178912fa36f87a957c15d1f1708c299.zip | |
firmware/sysfb: Fix VESA format selection
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@panix.com
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/firmware/sysfb_simplefb.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/firmware/sysfb_simplefb.c b/drivers/firmware/sysfb_simplefb.c index 82c64cb9f531..74363ed7501f 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; } |