| From c8be5edbd36ceed2ff3d6b8f8e40643c3f396ea3 Mon Sep 17 00:00:00 2001 |
| From: Michael Schmitz <schmitzmic@gmail.com> |
| Date: Wed, 16 Feb 2022 20:26:25 +1300 |
| Subject: video: fbdev: atari: Atari 2 bpp (STe) palette bugfix |
| |
| From: Michael Schmitz <schmitzmic@gmail.com> |
| |
| commit c8be5edbd36ceed2ff3d6b8f8e40643c3f396ea3 upstream. |
| |
| The code to set the shifter STe palette registers has a long |
| standing operator precedence bug, manifesting as colors set |
| on a 2 bits per pixel frame buffer coming up with a distinctive |
| blue tint. |
| |
| Add parentheses around the calculation of the per-color palette |
| data before shifting those into their respective bit field position. |
| |
| This bug goes back a long way (2.4 days at the very least) so there |
| won't be a Fixes: tag. |
| |
| Tested on ARAnyM as well on Falcon030 hardware. |
| |
| Cc: stable@vger.kernel.org |
| Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> |
| Link: https://lore.kernel.org/all/CAMuHMdU3ievhXxKR_xi_v3aumnYW7UNUO6qMdhgfyWTyVSsCkQ@mail.gmail.com |
| Tested-by: Michael Schmitz <schmitzmic@gmail.com> |
| Tested-by: Geert Uytterhoeven <geert@linux-m68k.org> |
| Signed-off-by: Michael Schmitz <schmitzmic@gmail.com> |
| Signed-off-by: Helge Deller <deller@gmx.de> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/video/fbdev/atafb.c | 12 ++++++------ |
| 1 file changed, 6 insertions(+), 6 deletions(-) |
| |
| --- a/drivers/video/fbdev/atafb.c |
| +++ b/drivers/video/fbdev/atafb.c |
| @@ -1692,9 +1692,9 @@ static int falcon_setcolreg(unsigned int |
| ((blue & 0xfc00) >> 8)); |
| if (regno < 16) { |
| shifter_tt.color_reg[regno] = |
| - (((red & 0xe000) >> 13) | ((red & 0x1000) >> 12) << 8) | |
| - (((green & 0xe000) >> 13) | ((green & 0x1000) >> 12) << 4) | |
| - ((blue & 0xe000) >> 13) | ((blue & 0x1000) >> 12); |
| + ((((red & 0xe000) >> 13) | ((red & 0x1000) >> 12)) << 8) | |
| + ((((green & 0xe000) >> 13) | ((green & 0x1000) >> 12)) << 4) | |
| + ((blue & 0xe000) >> 13) | ((blue & 0x1000) >> 12); |
| ((u32 *)info->pseudo_palette)[regno] = ((red & 0xf800) | |
| ((green & 0xfc00) >> 5) | |
| ((blue & 0xf800) >> 11)); |
| @@ -1980,9 +1980,9 @@ static int stste_setcolreg(unsigned int |
| green >>= 12; |
| if (ATARIHW_PRESENT(EXTD_SHIFTER)) |
| shifter_tt.color_reg[regno] = |
| - (((red & 0xe) >> 1) | ((red & 1) << 3) << 8) | |
| - (((green & 0xe) >> 1) | ((green & 1) << 3) << 4) | |
| - ((blue & 0xe) >> 1) | ((blue & 1) << 3); |
| + ((((red & 0xe) >> 1) | ((red & 1) << 3)) << 8) | |
| + ((((green & 0xe) >> 1) | ((green & 1) << 3)) << 4) | |
| + ((blue & 0xe) >> 1) | ((blue & 1) << 3); |
| else |
| shifter_tt.color_reg[regno] = |
| ((red & 0xe) << 7) | |
