On 10/21/25 9:32 AM, Thomas Zimmermann wrote:
Hi
Am 21.10.25 um 10:41 schrieb Mehdi Ben Hadj Khelifa:
On 10/21/25 7:51 AM, Thomas Zimmermann wrote:
Hi
Am 20.10.25 um 13:57 schrieb Mehdi Ben Hadj Khelifa:
Use drm_format_info_min_pitch() to calculate the framebuffer line pitch
instead of directly multiplying width and height. This aligns with DRM
helpers for determining per-line byte size and avoids manual
assumptions
about bytes per pixel.
Suggested-by: Thomas Zimmermann <[email protected]>
Signed-off-by: Mehdi Ben Hadj Khelifa <[email protected]>
---
drivers/gpu/drm/tiny/repaper.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/tiny/repaper.c b/drivers/gpu/drm/tiny/
repaper.c
index 4824f863fdba..aeff49bc6ba7 100644
--- a/drivers/gpu/drm/tiny/repaper.c
+++ b/drivers/gpu/drm/tiny/repaper.c
@@ -517,6 +517,8 @@ static int repaper_fb_dirty(struct
drm_framebuffer *fb, const struct iosys_map *
unsigned int dst_pitch = 0;
struct iosys_map dst;
struct drm_rect clip;
+ const struct drm_format_info *info = fb->format;
This is the wrong format. You're allocating the output buffer here,
but you're using the input format. IIUC the output format is
DRM_FORMAT_R1. The input is _XRGB8888.
Ah. Thanks for clarification.I thought since it had the same output
format. I will send a v3 shortly.> Best regards
Maybe just don't do it. This is just churn with no clear goal.
Okay,I will abort working on it.Though my goal was to remove the manual
assumption that height is multiple of 8 and to align with other
'correct' API used in other drm drivers as you suggested[1].
[1]:https://lore.kernel.org/all/[email protected]/
Best Regards,
Mehdi Ben Hadj Khelifa> Best regards
Thomas
Thomas
+ size_t pitch;
int idx, ret = 0;
u8 *buf = NULL;
@@ -534,7 +536,9 @@ static int repaper_fb_dirty(struct
drm_framebuffer *fb, const struct iosys_map *
DRM_DEBUG("Flushing [FB:%d] st=%ums\n", fb->base.id,
epd->factored_stage_time);
- buf = kmalloc(fb->width * fb->height / 8, GFP_KERNEL);
+ pitch = drm_format_info_min_pitch(info, 0, fb->width);
+
+ buf = kmalloc_array(fb->height, pitch, GFP_KERNEL);
if (!buf) {
ret = -ENOMEM;
goto out_exit;
