drm/nv50/crtc: Bail out if FB is not bound to crtc

Fixes possbile NULL pointer dereference
Resolves 'kernel crash in nv50_crtc_do_mode_set_base during shutdown'
https://bugs.freedesktop.org/show_bug.cgi?id=40005

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
This commit is contained in:
Emil Velikov 2011-08-21 22:48:12 +01:00 committed by Ben Skeggs
parent ddf28352b8
commit ffbc559b06

View File

@ -519,12 +519,18 @@ nv50_crtc_do_mode_set_base(struct drm_crtc *crtc,
struct drm_device *dev = nv_crtc->base.dev;
struct drm_nouveau_private *dev_priv = dev->dev_private;
struct nouveau_channel *evo = nv50_display(dev)->master;
struct drm_framebuffer *drm_fb = nv_crtc->base.fb;
struct nouveau_framebuffer *fb = nouveau_framebuffer(drm_fb);
struct drm_framebuffer *drm_fb;
struct nouveau_framebuffer *fb;
int ret;
NV_DEBUG_KMS(dev, "index %d\n", nv_crtc->index);
/* no fb bound */
if (!atomic && !crtc->fb) {
NV_DEBUG_KMS(dev, "No FB bound\n");
return 0;
}
/* If atomic, we want to switch to the fb we were passed, so
* now we update pointers to do that. (We don't pin; just
* assume we're already pinned and update the base address.)
@ -533,6 +539,8 @@ nv50_crtc_do_mode_set_base(struct drm_crtc *crtc,
drm_fb = passed_fb;
fb = nouveau_framebuffer(passed_fb);
} else {
drm_fb = crtc->fb;
fb = nouveau_framebuffer(crtc->fb);
/* If not atomic, we can go ahead and pin, and unpin the
* old fb we were passed.
*/