Hi Am 20.04.23 um 17:57 schrieb Pierre Asselin:
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);
I found this casting mess even more unreadable. I went back to v2, fixed the style issues and committed the patch as v4 (still under your name).
https://cgit.freedesktop.org/drm/drm-tip/commit/?id=1b617bc93178912fa36f87a957c15d1f1708c299 Thanks a lot for the bugfix. Best regard Thomas
} else { bits_per_pixel = si->lfb_depth; } base-commit: 6a8f57ae2eb07ab39a6f0ccad60c760743051026
-- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Frankenstrasse 146, 90461 Nuernberg, Germany GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman HRB 36809 (AG Nuernberg)
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