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 casts.
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.
Link: https://lore.kernel.org/r/4Psm6B6Lqkz1QXM@xxxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20230412150225.3757223-1-javierm@xxxxxxxxxx
Link: https://lore.kernel.org/dri-devel/20230418183325.2327-1-pa@xxxxxxxxx/T/#u
Link: https://lore.kernel.org/dri-devel/20230419044834.10816-1-pa@xxxxxxxxx/T/#u
Fixes: f35cd3fa7729 ("firmware/sysfb: Fix EFI/VESA format selection")
Signed-off-by: Pierre Asselin <pa@xxxxxxxxx>
---
drivers/firmware/sysfb_simplefb.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/drivers/firmware/sysfb_simplefb.c b/drivers/firmware/sysfb_simplefb.c
index 82c64cb9f531..6f7c5d0c5090 100644
--- a/drivers/firmware/sysfb_simplefb.c
+++ b/drivers/firmware/sysfb_simplefb.c
@@ -51,15 +51,18 @@ __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.
*/
if (si->lfb_depth > 8) {
- bits_per_pixel = max(max3(si->red_size + si->red_pos,
- si->green_size + si->green_pos,
- si->blue_size + si->blue_pos),
- si->rsvd_size + si->rsvd_pos);
+ /* max() macros args should be of the same type */
+ bits_per_pixel = max3((u16)max3(si->red_size + si->red_pos,
+ si->green_size + si->green_pos,
+ si->blue_size + si->blue_pos),
+ (u16)(si->rsvd_size + si->rsvd_pos),
+ si->lfb_depth);
} else {
bits_per_pixel = si->lfb_depth;
}
base-commit: 6a8f57ae2eb07ab39a6f0ccad60c760743051026
--
2.39.2
