drm/atmel-hlcdc: don't reject the commit if the src rect has fractional parts

Don’t reject the commit when the source rectangle has fractional parts.
This can occur due to scaling: drm_atomic_helper_check_plane_state() calls
drm_rect_clip_scaled(), which may introduce fractional parts while
computing the clipped source rectangle. This does not imply the commit is
invalid, so we should accept it instead of discarding it.

Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Reviewed-by: Manikandan Muralidharan <manikandan.m@microchip.com>
Link: https://patch.msgid.link/20251120-lcd_scaling_fix-v1-1-5ffc98557923@microchip.com
Signed-off-by: Manikandan Muralidharan <manikandan.m@microchip.com>

diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c
index 00dd4fcb0d31ab733922f98fd563dc72e1c8a7f0..c52da47982ee5e23d5e6ded272b0c0b6a10269f7 100644 (file)
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c
@@ -79,8 +79,6 @@ drm_plane_state_to_atmel_hlcdc_plane_state(struct drm_plane_state *s)
        return container_of(s, struct atmel_hlcdc_plane_state, base);
 }
 
-#define SUBPIXEL_MASK                  0xffff
-
 static uint32_t rgb_formats[] = {
        DRM_FORMAT_C8,
        DRM_FORMAT_XRGB4444,
@@ -745,24 +743,15 @@ static int atmel_hlcdc_plane_atomic_check(struct drm_plane *p,
        if (ret || !s->visible)
                return ret;
 
-       hstate->src_x = s->src.x1;
-       hstate->src_y = s->src.y1;
-       hstate->src_w = drm_rect_width(&s->src);
-       hstate->src_h = drm_rect_height(&s->src);
+       hstate->src_x = s->src.x1 >> 16;
+       hstate->src_y = s->src.y1 >> 16;
+       hstate->src_w = drm_rect_width(&s->src) >> 16;
+       hstate->src_h = drm_rect_height(&s->src) >> 16;
        hstate->crtc_x = s->dst.x1;
        hstate->crtc_y = s->dst.y1;
        hstate->crtc_w = drm_rect_width(&s->dst);
        hstate->crtc_h = drm_rect_height(&s->dst);
 
-       if ((hstate->src_x | hstate->src_y | hstate->src_w | hstate->src_h) &
-           SUBPIXEL_MASK)
-               return -EINVAL;
-
-       hstate->src_x >>= 16;
-       hstate->src_y >>= 16;
-       hstate->src_w >>= 16;
-       hstate->src_h >>= 16;
-
        hstate->nplanes = fb->format->num_planes;
        if (hstate->nplanes > ATMEL_HLCDC_LAYER_MAX_PLANES)
                return -EINVAL;