diff options
| author | Thomas Zimmermann <tzimmermann@suse.de> | 2022-03-13 20:29:52 +0100 |
|---|---|---|
| committer | Dave Airlie <airlied@redhat.com> | 2022-03-25 09:55:54 +1000 |
| commit | 2a81dba4b577099717cea86d429f053e85e74d96 (patch) | |
| tree | 2ef8087a601aa83933d18a0a5347865ab31a51b1 /drivers/video | |
| parent | 40faaf80c463b2c99a0351d28bd74d75d64ed017 (diff) | |
| download | linux-2a81dba4b577099717cea86d429f053e85e74d96.tar.bz2 | |
fbdev: Fix cfb_imageblit() for arbitrary image widths
Commit 0d03011894d2 ("fbdev: Improve performance of cfb_imageblit()")
broke cfb_imageblit() for image widths that are not aligned to 8-bit
boundaries. Fix this by handling the trailing pixels on each line
separately. The performance improvements in the original commit do not
regress by this change.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 0d03011894d2 ("fbdev: Improve performance of cfb_imageblit()")
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Javier Martinez Canillas <javierm@redhat.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220313192952.12058-3-tzimmermann@suse.de
Diffstat (limited to 'drivers/video')
| -rw-r--r-- | drivers/video/fbdev/core/cfbimgblt.c | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/drivers/video/fbdev/core/cfbimgblt.c b/drivers/video/fbdev/core/cfbimgblt.c index 7361cfabdd85..9ebda4e0dc7a 100644 --- a/drivers/video/fbdev/core/cfbimgblt.c +++ b/drivers/video/fbdev/core/cfbimgblt.c @@ -218,7 +218,7 @@ static inline void fast_imageblit(const struct fb_image *image, struct fb_info * { u32 fgx = fgcolor, bgx = bgcolor, bpp = p->var.bits_per_pixel; u32 ppw = 32/bpp, spitch = (image->width + 7)/8; - u32 bit_mask, eorx; + u32 bit_mask, eorx, shift; const char *s = image->data, *src; u32 __iomem *dst; const u32 *tab = NULL; @@ -259,17 +259,23 @@ static inline void fast_imageblit(const struct fb_image *image, struct fb_info * for (i = image->height; i--; ) { dst = (u32 __iomem *)dst1; + shift = 8; src = s; + /* + * Manually unroll the per-line copying loop for better + * performance. This works until we processed the last + * completely filled source byte (inclusive). + */ switch (ppw) { case 4: /* 8 bpp */ - for (j = k; j; j -= 2, ++src) { + for (j = k; j >= 2; j -= 2, ++src) { FB_WRITEL(colortab[(*src >> 4) & bit_mask], dst++); FB_WRITEL(colortab[(*src >> 0) & bit_mask], dst++); } break; case 2: /* 16 bpp */ - for (j = k; j; j -= 4, ++src) { + for (j = k; j >= 4; j -= 4, ++src) { FB_WRITEL(colortab[(*src >> 6) & bit_mask], dst++); FB_WRITEL(colortab[(*src >> 4) & bit_mask], dst++); FB_WRITEL(colortab[(*src >> 2) & bit_mask], dst++); @@ -277,7 +283,7 @@ static inline void fast_imageblit(const struct fb_image *image, struct fb_info * } break; case 1: /* 32 bpp */ - for (j = k; j; j -= 8, ++src) { + for (j = k; j >= 8; j -= 8, ++src) { FB_WRITEL(colortab[(*src >> 7) & bit_mask], dst++); FB_WRITEL(colortab[(*src >> 6) & bit_mask], dst++); FB_WRITEL(colortab[(*src >> 5) & bit_mask], dst++); @@ -290,6 +296,20 @@ static inline void fast_imageblit(const struct fb_image *image, struct fb_info * break; } + /* + * For image widths that are not a multiple of 8, there + * are trailing pixels left on the current line. Print + * them as well. + */ + for (; j--; ) { + shift -= ppw; + FB_WRITEL(colortab[(*src >> shift) & bit_mask], dst++); + if (!shift) { + shift = 8; + ++src; + } + } + dst1 += p->fix.line_length; s += spitch; } |