drm/radeon/kms: balance asic_reset functions

First, we were calling mc_stop() at the top of the function
which turns off all MC (memory controller) clients,
then checking if the GPU is idle.  If it was idle we
returned without re-enabling the MC clients which would
lead to a blank screen, etc.  This patch checks if the
GPU is idle before calling mc_stop().

Second, if the reset failed, we were returning without
re-enabling the MC clients.  This patch re-enables
the MC clients before returning regardless of whether
the reset was successful or not.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

3 files changed, 20 insertions, 18 deletions

diff --git a/drivers/gpu/drm/radeon/r100.c b/drivers/gpu/drm/radeon/r100.c
index f637595b14e1..46da5142b131 100644
--- a/drivers/gpu/drm/radeon/r100.c
+++ b/drivers/gpu/drm/radeon/r100.c
@@ -2086,12 +2086,13 @@ int r100_asic_reset(struct radeon_device *rdev)
 {
         struct r100_mc_save save;
         u32 status, tmp;
+        int ret = 0;
 
-        r100_mc_stop(rdev, &save);
         status = RREG32(R_000E40_RBBM_STATUS);
         if (!G_000E40_GUI_ACTIVE(status)) {
                 return 0;
         }
+        r100_mc_stop(rdev, &save);
         status = RREG32(R_000E40_RBBM_STATUS);
         dev_info(rdev->dev, "(%s:%d) RBBM_STATUS=0x%08X\n", __func__, __LINE__, status);
         /* stop CP */
@@ -2131,11 +2132,11 @@ int r100_asic_reset(struct radeon_device *rdev)
                 G_000E40_TAM_BUSY(status) || G_000E40_PB_BUSY(status)) {
                 dev_err(rdev->dev, "failed to reset GPU\n");
                 rdev->gpu_lockup = true;
-                return -1;
-        }
+                ret = -1;
+        } else
+                dev_info(rdev->dev, "GPU reset succeed\n");
         r100_mc_resume(rdev, &save);
-        dev_info(rdev->dev, "GPU reset succeed\n");
-        return 0;
+        return ret;
 }
 
 void r100_set_common_regs(struct radeon_device *rdev)
diff --git a/drivers/gpu/drm/radeon/r300.c b/drivers/gpu/drm/radeon/r300.c
index fae5e709f270..cf862ca580bf 100644
--- a/drivers/gpu/drm/radeon/r300.c
+++ b/drivers/gpu/drm/radeon/r300.c
@@ -405,12 +405,13 @@ int r300_asic_reset(struct radeon_device *rdev)
 {
         struct r100_mc_save save;
         u32 status, tmp;
+        int ret = 0;
 
-        r100_mc_stop(rdev, &save);
         status = RREG32(R_000E40_RBBM_STATUS);
         if (!G_000E40_GUI_ACTIVE(status)) {
                 return 0;
         }
+        r100_mc_stop(rdev, &save);
         status = RREG32(R_000E40_RBBM_STATUS);
         dev_info(rdev->dev, "(%s:%d) RBBM_STATUS=0x%08X\n", __func__, __LINE__, status);
         /* stop CP */
@@ -451,11 +452,11 @@ int r300_asic_reset(struct radeon_device *rdev)
         if (G_000E40_GA_BUSY(status) || G_000E40_VAP_BUSY(status)) {
                 dev_err(rdev->dev, "failed to reset GPU\n");
                 rdev->gpu_lockup = true;
-                return -1;
-        }
+                ret = -1;
+        } else
+                dev_info(rdev->dev, "GPU reset succeed\n");
         r100_mc_resume(rdev, &save);
-        dev_info(rdev->dev, "GPU reset succeed\n");
-        return 0;
+        return ret;
 }
 
 /*
diff --git a/drivers/gpu/drm/radeon/rs600.c b/drivers/gpu/drm/radeon/rs600.c
index b4192acaab5f..5afe294ed51f 100644
--- a/drivers/gpu/drm/radeon/rs600.c
+++ b/drivers/gpu/drm/radeon/rs600.c
@@ -339,16 +339,16 @@ void rs600_bm_disable(struct radeon_device *rdev)
 
 int rs600_asic_reset(struct radeon_device *rdev)
 {
-        u32 status, tmp;
-
         struct rv515_mc_save save;
+        u32 status, tmp;
+        int ret = 0;
 
-        /* Stops all mc clients */
-        rv515_mc_stop(rdev, &save);
         status = RREG32(R_000E40_RBBM_STATUS);
         if (!G_000E40_GUI_ACTIVE(status)) {
                 return 0;
         }
+        /* Stops all mc clients */
+        rv515_mc_stop(rdev, &save);
         status = RREG32(R_000E40_RBBM_STATUS);
         dev_info(rdev->dev, "(%s:%d) RBBM_STATUS=0x%08X\n", __func__, __LINE__, status);
         /* stop CP */
@@ -392,11 +392,11 @@ int rs600_asic_reset(struct radeon_device *rdev)
         if (G_000E40_GA_BUSY(status) || G_000E40_VAP_BUSY(status)) {
                 dev_err(rdev->dev, "failed to reset GPU\n");
                 rdev->gpu_lockup = true;
-                return -1;
-        }
+                ret = -1;
+        } else
+                dev_info(rdev->dev, "GPU reset succeed\n");
         rv515_mc_resume(rdev, &save);
-        dev_info(rdev->dev, "GPU reset succeed\n");
-        return 0;
+        return ret;
 }
 
 /*