Hi,
It looks like there can be an infinite loop if neither of the if()'s become true.
Is that an impossible condition?
-----Original Message-----
From: Andrey Grodzovsky <andrey.grodzovsky@xxxxxxx>
Sent: Tuesday, April 24, 2018 11:31 AM
To: linux-kernel at vger.kernel.org; amd-gfx at lists.freedesktop.org
Cc: Deucher, Alexander <Alexander.Deucher at amd.com>; Koenig, Christian <Christian.Koenig at amd.com>; Panariti, David <David.Panariti at amd.com>; oleg at redhat.com; akpm at linux-foundation.org; ebiederm at xmission.com; Grodzovsky, Andrey <Andrey.Grodzovsky at amd.com>
Subject: [PATCH 3/3] drm/amdgpu: Switch to interrupted wait to recover from ring hang.
If the ring is hanging for some reason allow to recover the waiting by sending fatal signal.
Originally-by: David Panariti <David.Panariti at amd.com>
Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky at amd.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
index eb80edf..37a36af 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
@@ -421,10 +421,16 @@ int amdgpu_ctx_wait_prev_fence(struct amdgpu_ctx *ctx, unsigned ring_id)
if (other) {
signed long r;
- r = dma_fence_wait_timeout(other, false, MAX_SCHEDULE_TIMEOUT);
- if (r < 0) {
- DRM_ERROR("Error (%ld) waiting for fence!\n", r);
- return r;
+
+ while (true) {
+ if ((r = dma_fence_wait_timeout(other, true,
+ MAX_SCHEDULE_TIMEOUT)) >= 0)
+ return 0;
+
+ if (fatal_signal_pending(current)) {
+ DRM_ERROR("Error (%ld) waiting for fence!\n", r);
+ return r;
+ }
}
}
--
2.7.4
