[PATCH xf86-video-amdgpu] Check dimensions passed to drmmode_xf86crtc_resize

[Michel Dänzer]

From: Michel Dänzer <michel.daenzer at amd.com>

When enabling a secondary GPU output, Xorg can try resizing the screen
beyond the limit advertised by the driver, leading to drmModeAddFB
failing and primary GPU outputs turning off. Check for this and bail
instead.

Signed-off-by: Michel Dänzer <michel.daenzer at amd.com>
---
 src/drmmode_display.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/drmmode_display.c b/src/drmmode_display.c
index 8a1a201a8..a23724770 100644
--- a/src/drmmode_display.c
+++ b/src/drmmode_display.c
@@ -2191,6 +2191,14 @@ static Bool drmmode_xf86crtc_resize(ScrnInfoPtr scrn, int width, int height)
 	if (scrn->virtualX == width && scrn->virtualY == height)
 		return TRUE;
 
+	if (width > xf86_config->maxWidth || height > xf86_config->maxHeight) {
+		xf86DrvMsg(scrn->scrnIndex, X_ERROR,
+			   "Xorg tried resizing screen to %dx%d, but maximum "
+			   "supported is %dx%d\n", width, height,
+			   xf86_config->maxWidth, xf86_config->maxHeight);
+		return FALSE;
+	}
+
 	if (info->shadow_primary)
 		hint = AMDGPU_CREATE_PIXMAP_LINEAR | AMDGPU_CREATE_PIXMAP_GTT;
 	else if (!info->use_glamor)
-- 
2.17.1