[PATCH] drm/radeon: improve semaphore debugging on lockup

[j.glisse at gmail.com]

From: Jerome Glisse <jglisse at redhat.com>

Signed-off-by: Jerome Glisse <jglisse at redhat.com>
---
 drivers/gpu/drm/radeon/radeon.h           | 2 ++
 drivers/gpu/drm/radeon/radeon_ring.c      | 2 ++
 drivers/gpu/drm/radeon/radeon_semaphore.c | 4 ++++
 3 files changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 9b9422c..f0bb8d5 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -649,6 +649,8 @@ struct radeon_ring {
 	u32			ptr_reg_mask;
 	u32			nop;
 	u32			idx;
+	u64			last_semaphore_signal_addr;
+	u64			last_semaphore_wait_addr;
 };
 
 /*
diff --git a/drivers/gpu/drm/radeon/radeon_ring.c b/drivers/gpu/drm/radeon/radeon_ring.c
index 141f2b6..2430d80 100644
--- a/drivers/gpu/drm/radeon/radeon_ring.c
+++ b/drivers/gpu/drm/radeon/radeon_ring.c
@@ -784,6 +784,8 @@ static int radeon_debugfs_ring_info(struct seq_file *m, void *data)
 	}
 	seq_printf(m, "driver's copy of the wptr: 0x%08x [%5d]\n", ring->wptr, ring->wptr);
 	seq_printf(m, "driver's copy of the rptr: 0x%08x [%5d]\n", ring->rptr, ring->rptr);
+	seq_printf(m, "last semaphore signal addr : 0x%016llx\n", ring->last_semaphore_signal_addr);
+	seq_printf(m, "last semaphore wait addr   : 0x%016llx\n", ring->last_semaphore_wait_addr);
 	seq_printf(m, "%u free dwords in ring\n", ring->ring_free_dw);
 	seq_printf(m, "%u dwords in ring\n", count);
 	/* print 8 dw before current rptr as often it's the last executed
diff --git a/drivers/gpu/drm/radeon/radeon_semaphore.c b/drivers/gpu/drm/radeon/radeon_semaphore.c
index 97f3ece..8dcc20f 100644
--- a/drivers/gpu/drm/radeon/radeon_semaphore.c
+++ b/drivers/gpu/drm/radeon/radeon_semaphore.c
@@ -95,6 +95,10 @@ int radeon_semaphore_sync_rings(struct radeon_device *rdev,
 	/* we assume caller has already allocated space on waiters ring */
 	radeon_semaphore_emit_wait(rdev, waiter, semaphore);
 
+	/* for debugging lockup only, used by sysfs debug files */
+	rdev->ring[signaler].last_semaphore_signal_addr = semaphore->gpu_addr;
+	rdev->ring[waiter].last_semaphore_wait_addr = semaphore->gpu_addr;
+
 	return 0;
 }
 
-- 
1.7.11.7