radeon_gem_wait_idle_ioctl can apparently get called prior to the vram page being set up or even if accel if false, so make sure it's valid before using it.

Should fix: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=597636 https://bugs.freedesktop.org/show_bug.cgi?id=29834

Signed-off-by: Alex Deucher alexdeucher@gmail.com Cc: stable@kernel.org --- drivers/gpu/drm/radeon/r600.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c index 30a51c3..31f45af 100644 --- a/drivers/gpu/drm/radeon/r600.c +++ b/drivers/gpu/drm/radeon/r600.c @@ -3491,7 +3491,8 @@ void r600_ioctl_wait_idle(struct radeon_device *rdev, struct radeon_bo *bo) /* r7xx hw bug. write to HDP_DEBUG1 followed by fb read * rather than write to HDP_REG_COHERENCY_FLUSH_CNTL */ - if ((rdev->family >= CHIP_RV770) && (rdev->family <= CHIP_RV740)) { + if ((rdev->family >= CHIP_RV770) && (rdev->family <= CHIP_RV740) && + rdev->vram_scratch.ptr) { void __iomem *ptr = (void *)rdev->vram_scratch.ptr; u32 tmp;