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| author | Linmao Li <lilinmao@kylinos.cn> | 2026-08-27 17:39:48 +0800 |
|---|---|---|
| committer | Helge Deller <deller@gmx.de> | 2026-09-10 22:36:31 +0200 |
| commit | 3934185ba63feca6e80cc8b90f7d7f01cde78223 (patch) | |
| tree | 3623f96cf5555517e6919c1c77952fadb1be6914 | |
| parent | 3fb13d29cf8eb4502837bff06b2873c5435f6ffd (diff) | |
| download | linux-3934185ba63feca6e80cc8b90f7d7f01cde78223.tar.gz linux-3934185ba63feca6e80cc8b90f7d7f01cde78223.zip | |
fbdev: atafb: Restrict SuperBlitter to supported formats
The SuperBlitter operations derive an integer byte count per pixel. The
accelerated fill path handles only one-, two- and four-byte pixels.
However, the operations are currently installed for every external
framebuffer in SuperVidel RAM, including planar 1/2/4/8-bpp and 24-bpp
truecolor modes accepted by the external video parser.
For 1/2/4-bpp modes, the byte count becomes zero, so accelerated copies do
nothing and fills fall through to 32-bit stores. Planar 8-bpp uses an
incompatible memory layout. For 24-bpp modes, fills also use 32-bit stores
despite advancing addresses by three bytes per pixel. These cases can
corrupt the framebuffer beyond the requested rectangle.
Enable the SuperBlitter operations only for the layouts they implement:
8-bpp packed pixels and 16/32-bpp truecolor. Keep the existing software
operations for all other external formats.
Fixes: d463633d63e6 ("fbdev: atafb: Add support for SuperVidel's SuperBlitter")
Signed-off-by: Linmao Li <lilinmao@kylinos.cn>
Tested-by: Miro Kropáček <miro.kropacek@gmail.com>
Reviewed-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
| -rw-r--r-- | drivers/video/fbdev/atafb.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/video/fbdev/atafb.c b/drivers/video/fbdev/atafb.c index 5bca34c45cef..c3011b61a94b 100644 --- a/drivers/video/fbdev/atafb.c +++ b/drivers/video/fbdev/atafb.c @@ -3360,7 +3360,11 @@ static int __init atafb_probe(struct platform_device *pdev) memset (screen_base, 0, external_len); /* framebuffer in SV RAM: enable the SuperBlitter */ - if (external_addr >= 0xa0000000) { + if (external_addr >= 0xa0000000 && + ((external_pmode == FB_TYPE_PACKED_PIXELS && + external_depth == 8) || + (external_pmode == -1 && + (external_depth == 16 || external_depth == 32)))) { svblit_regs = ioremap(SVBLIT_REGS_PHYS, 0x100); if (svblit_regs) { svblit_fw = svblit_rd(SVBLIT_VERSION) & 0x1ff; |