[Nouveau] [PATCH v2] nouveau/dispnv50: add cursor pitch check

[Simon Ser]

The hardware needs a FB which is packed. Add checks to make sure
this is the case.

While at it, add debug logs for the existing checks. This allows
user-space to more easily figure out why a configuration is
rejected.

v2:
- Use drm_format_info instead of hardcoding bytes-per-pixel (Ilia)
- Remove unnecessary size check (Ilia)

Signed-off-by: Simon Ser <contact at emersion.fr>
Cc: Lyude Paul <lyude at redhat.com>
Cc: Ben Skeggs <bskeggs at redhat.com>
Cc: Ilia Mirkin <imirkin at alum.mit.edu>
---
 drivers/gpu/drm/nouveau/dispnv50/curs507a.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/dispnv50/curs507a.c b/drivers/gpu/drm/nouveau/dispnv50/curs507a.c
index 54fbd6fe751d..00f09c9a8d15 100644
--- a/drivers/gpu/drm/nouveau/dispnv50/curs507a.c
+++ b/drivers/gpu/drm/nouveau/dispnv50/curs507a.c
@@ -30,6 +30,7 @@
 
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_plane_helper.h>
+#include <drm/drm_fourcc.h>
 
 bool
 curs507a_space(struct nv50_wndw *wndw)
@@ -99,6 +100,8 @@ curs507a_acquire(struct nv50_wndw *wndw, struct nv50_wndw_atom *asyw,
 		 struct nv50_head_atom *asyh)
 {
 	struct nv50_head *head = nv50_head(asyw->state.crtc);
+	struct drm_device *dev = head->base.base.dev;
+	struct drm_framebuffer *fb = asyw->state.fb;
 	int ret;
 
 	ret = drm_atomic_helper_check_plane_state(&asyw->state, &asyh->state,
@@ -109,12 +112,26 @@ curs507a_acquire(struct nv50_wndw *wndw, struct nv50_wndw_atom *asyw,
 	if (ret || !asyh->curs.visible)
 		return ret;
 
-	if (asyw->image.w != asyw->image.h)
+	if (asyw->image.w != asyw->image.h) {
+		drm_dbg_atomic(dev,
+			       "Invalid cursor image size: width (%d) must match height (%d)",
+			       asyw->image.w, asyw->image.h);
 		return -EINVAL;
+	}
+	if (asyw->image.pitch[0] != asyw->image.w * fb->format->cpp[0]) {
+		drm_dbg_atomic(dev,
+			       "Invalid cursor image pitch: image must be packed (pitch = %d, width = %d)",
+			       asyw->image.pitch[0], asyw->image.w);
+		return -EINVAL;
+	}
 
 	ret = head->func->curs_layout(head, asyw, asyh);
-	if (ret)
+	if (ret) {
+		drm_dbg_atomic(dev,
+			       "Invalid cursor image size: unsupported size %dx%d",
+			       asyw->image.w, asyw->image.h);
 		return ret;
+	}
 
 	return head->func->curs_format(head, asyw, asyh);
 }
-- 
2.30.0