[PATCH] staging: sm750fb: fix mono image source stride mismatch in lynxfb_ops_imageblit()
Muhammad Bilal <[email protected]> Sat, 18 Jul 2026 09:56:41 +0500
| Newsgroups | org.kernel.vger.linux-fbdev,dev.linux.lists.linux-staging,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <[email protected]> |
sm750_hw_imageblit() advances its monochrome source pointer by src_delta per scanline, and computes the correct rounded-up stride internally as: bytes_per_scan = (width + start_bit + 7) / 8; Its only caller, lynxfb_ops_imageblit(), instead passes src_delta as image->width >> 3. For widths not a multiple of 8 this under-counts the stride, so the source pointer falls further behind the real per-scanline layout on every line, corrupting the rendered image. Use DIV_ROUND_UP() so the stride passed in matches what sm750_hw_imageblit() already assumes. Signed-off-by: Muhammad Bilal <[email protected]> --- drivers/staging/sm750fb/sm750.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/staging/sm750fb/sm750.c b/drivers/staging/sm750fb/sm750.c index 89c811e0806c..69e803f4f175 100644 --- a/drivers/staging/sm750fb/sm750.c +++ b/drivers/staging/sm750fb/sm750.c @@ -261,7 +261,7 @@ static void lynxfb_ops_imageblit(struct fb_info *info, spin_lock(&sm750_dev->slock); sm750_dev->accel.de_imageblit(&sm750_dev->accel, - image->data, image->width >> 3, 0, + image->data, DIV_ROUND_UP(image->width, 8), 0, base, pitch, bpp, image->dx, image->dy, image->width, image->height, -- 2.55.0