From 0d9a95099dcb05b5f4719c830d15bf4fdcad0dc2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20K=C3=B6nig?= <christian.koenig@amd.com>
Date: Tue, 14 Jan 2025 13:51:39 +0100
Subject: [PATCH] drm/amdgpu: grab an additional reference on the gang fence v2
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We keep the gang submission fence around in adev, make sure that it
stays alive.
v2: fix memory leak on retry
Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index e63bcd5edab97..35ace1368b9ca 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -6913,18 +6913,26 @@ struct dma_fence *amdgpu_device_switch_gang(struct amdgpu_device *adev,
{
struct dma_fence *old = NULL;
+ dma_fence_get(gang);
do {
dma_fence_put(old);
old = amdgpu_device_get_gang(adev);
if (old == gang)
break;
- if (!dma_fence_is_signaled(old))
+ if (!dma_fence_is_signaled(old)) {
+ dma_fence_put(gang);
return old;
+ }
} while (cmpxchg((struct dma_fence __force **)&adev->gang_submit,
old, gang) != old);
+ /*
+ * Drop it once for the exchanged reference in adev and once for the
+ * thread local reference acquired in amdgpu_device_get_gang().
+ */
+ dma_fence_put(old);
dma_fence_put(old);
return NULL;
}
--
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