Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> writes:
Hello Geert,
Thanks for your patch!
> The page height must be taken into account only for vertical coordinates
> and heights, not for horizontal coordinates and widths.
>
> Fixes: 179a790aaf2a0127 ("drm/ssd130x: Set the page height value in the device info data")
> Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/solomon/ssd130x.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/solomon/ssd130x.c b/drivers/gpu/drm/solomon/ssd130x.c
> index afb08a8aa9fcdaf2..b4c376962629580b 100644
> --- a/drivers/gpu/drm/solomon/ssd130x.c
> +++ b/drivers/gpu/drm/solomon/ssd130x.c
> @@ -596,7 +596,7 @@ static int ssd130x_fb_blit_rect(struct drm_framebuffer *fb, const struct iosys_m
> rect->y1 = round_down(rect->y1, page_height);
> rect->y2 = min_t(unsigned int, round_up(rect->y2, page_height), ssd130x->height);
>
> - dst_pitch = DIV_ROUND_UP(drm_rect_width(rect), page_height);
> + dst_pitch = DIV_ROUND_UP(drm_rect_width(rect), 8);
>
That's true for ssd130x controllers that use R1, but when doing that
change one of my goals was to prepare the driver for supporting the
ssd132x family that use a 16-grayscale pixel format (R4).
For those controllers, the pixels are encoded in 4-bit and each page
has two pixels. So for those controllers the dst_pitch will need to
be DIV_ROUND_UP(drm_rect_width(rect), 2) instead since the width is
not 8 in that case.
So I would prefer to skip this patch from your set, because otherwise
we will need to revert it when adding support for SSD132x controllers.
--
Best regards,
Javier Martinez Canillas
Core Platforms
Red Hat
