drm/radeon: clear reset flags if engines are idle

Fixes a hard lock in the gpu reset code after the
rework for DMA support (0ecebb9e0d14e9948e0b1529883a776758117d6f
"drm/radeon: switch to a finer grained reset for evergreen")
due to not bailing before the MC shutdown if the relevant engines
are idle.

Discussion:
http://lists.freedesktop.org/archives/dri-devel/2013-January/032985.html

Reported-by: Eldad Zack <eldad@fogrefinery.com>
Tested-by: Eldad Zack <eldad@fogrefinery.com>
Acked-by: Paul Menzel <paulepanter@users.sourceforge.net>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

4 files changed, 24 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c
index 061fa0a28900..4d0e60adbc6d 100644
--- a/drivers/gpu/drm/radeon/evergreen.c
+++ b/drivers/gpu/drm/radeon/evergreen.c
@@ -2401,6 +2401,12 @@ static int evergreen_gpu_soft_reset(struct radeon_device *rdev, u32 reset_mask)
 {
         struct evergreen_mc_save save;
 
+        if (!(RREG32(GRBM_STATUS) & GUI_ACTIVE))
+                reset_mask &= ~(RADEON_RESET_GFX | RADEON_RESET_COMPUTE);
+
+        if (RREG32(DMA_STATUS_REG) & DMA_IDLE)
+                reset_mask &= ~RADEON_RESET_DMA;
+
         if (reset_mask == 0)
                 return 0;
 
diff --git a/drivers/gpu/drm/radeon/ni.c b/drivers/gpu/drm/radeon/ni.c
index 896f1cbc58a5..59acabb45c9b 100644
--- a/drivers/gpu/drm/radeon/ni.c
+++ b/drivers/gpu/drm/radeon/ni.c
@@ -1409,6 +1409,12 @@ static int cayman_gpu_soft_reset(struct radeon_device *rdev, u32 reset_mask)
 {
         struct evergreen_mc_save save;
 
+        if (!(RREG32(GRBM_STATUS) & GUI_ACTIVE))
+                reset_mask &= ~(RADEON_RESET_GFX | RADEON_RESET_COMPUTE);
+
+        if (RREG32(DMA_STATUS_REG) & DMA_IDLE)
+                reset_mask &= ~RADEON_RESET_DMA;
+
         if (reset_mask == 0)
                 return 0;
 
diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index 537e259b3837..3cb9d6089373 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -1378,6 +1378,12 @@ static int r600_gpu_soft_reset(struct radeon_device *rdev, u32 reset_mask)
 {
         struct rv515_mc_save save;
 
+        if (!(RREG32(GRBM_STATUS) & GUI_ACTIVE))
+                reset_mask &= ~(RADEON_RESET_GFX | RADEON_RESET_COMPUTE);
+
+        if (RREG32(DMA_STATUS_REG) & DMA_IDLE)
+                reset_mask &= ~RADEON_RESET_DMA;
+
         if (reset_mask == 0)
                 return 0;
 
diff --git a/drivers/gpu/drm/radeon/si.c b/drivers/gpu/drm/radeon/si.c
index 3240a3d64f30..ae8b48205a6c 100644
--- a/drivers/gpu/drm/radeon/si.c
+++ b/drivers/gpu/drm/radeon/si.c
@@ -2215,6 +2215,12 @@ static int si_gpu_soft_reset(struct radeon_device *rdev, u32 reset_mask)
 {
         struct evergreen_mc_save save;
 
+        if (!(RREG32(GRBM_STATUS) & GUI_ACTIVE))
+                reset_mask &= ~(RADEON_RESET_GFX | RADEON_RESET_COMPUTE);
+
+        if (RREG32(DMA_STATUS_REG) & DMA_IDLE)
+                reset_mask &= ~RADEON_RESET_DMA;
+
         if (reset_mask == 0)
                 return 0;