From 16c58081eb95e35f284421176f355eccfc773bbe Mon Sep 17 00:00:00 2001 From: Simon Kitching Date: Thu, 20 Sep 2012 12:59:16 -0400 Subject: [PATCH] drm/radeon: Prevent leak of scratch register on resume from suspend Cards typically have 5-7 scratch registers; one of these is reserved for rdev->rptr_save_reg. Unfortunately the reservation is done in function r100_cp_init, which is called by all drivers except r600 - and this function is also invoked on resume from suspend. After several resumes, no scratch registers are free and graphics acceleration is disabled. Dmesg then reports either: *ERROR* radeon: cp failed to get scratch reg (-22). *ERROR* radeon: cp isn't working(-22). radeon 0000:01:00.0: failed initializing CP (-22). or: *ERROR* radeon: failed to get scratch reg (-22). *ERROR* radeon: failed testing IB on GFX ring (-22). *ERROR* ib ring test failed (-22). The chain of calls on boot for all except r600 is: radeon_init -> ... -> (rXXX_init) -> rXXX_startup -> r100_cp_init The chain of calls on resume for all except r600 is: rXXX_resume -> rXXX_startup -> r100_cp_init. R600 correctly allocates rptr_save_reg in r600_init (ie once only, not in resume). However moving the code into the init functions for all drivers means touching 4 drivers. So instead, this patch just adds a test in r100_cp_init to avoid reallocating on resume. As the rdev structure is allocated via kzalloc in radeon_driver_load_kms, and zero is not a valid registerid, zero safely implies not-yet-allocated. This issue appears to have been introduced in c7eff978 (3.6.0-rcN) Signed-off-by: Simon Kitching Signed-off-by: Alex Deucher --- drivers/gpu/drm/radeon/r100.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/radeon/r100.c b/drivers/gpu/drm/radeon/r100.c index 8acb34fd3fd5..8d7e33a0b243 100644 --- a/drivers/gpu/drm/radeon/r100.c +++ b/drivers/gpu/drm/radeon/r100.c @@ -1182,7 +1182,8 @@ int r100_cp_init(struct radeon_device *rdev, unsigned ring_size) ring->ready = true; radeon_ttm_set_active_vram_size(rdev, rdev->mc.real_vram_size); - if (radeon_ring_supports_scratch_reg(rdev, ring)) { + if (!ring->rptr_save_reg /* not resuming from suspend */ + && radeon_ring_supports_scratch_reg(rdev, ring)) { r = radeon_scratch_get(rdev, &ring->rptr_save_reg); if (r) { DRM_ERROR("failed to get scratch reg for rptr save (%d).\n", r); -- 2.34.1