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authorMichael Schmitz <schmitzmic@gmail.com>2022-02-16 20:26:25 +1300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-04-15 14:14:41 +0200
commit508248cfa87bed35c7ff8d7d3f87816129c1da0a (patch)
tree87427300fd2d1e5986c0b9cf256aacb5a0cd1102
parent1caa40af491dcfe17b3ae870a854388d8ea01984 (diff)
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video: fbdev: atari: Atari 2 bpp (STe) palette bugfix
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>
-rw-r--r--drivers/video/fbdev/atafb.c12
1 files changed, 6 insertions, 6 deletions
diff --git a/drivers/video/fbdev/atafb.c b/drivers/video/fbdev/atafb.c
index fcd2dd670a65..770f77055682 100644
--- a/drivers/video/fbdev/atafb.c
+++ b/drivers/video/fbdev/atafb.c
@@ -1713,9 +1713,9 @@ static int falcon_setcolreg(unsigned int regno, unsigned int red,
((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));
@@ -2001,9 +2001,9 @@ static int stste_setcolreg(unsigned int regno, unsigned int red,
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) |