From 2b59b0812d67b6376619625083507e38ff76a769 Mon Sep 17 00:00:00 2001
From: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Thu, 26 Aug 2021 11:33:34 +0200
Subject: drm/msm: Improve drm/sched point of no return rules
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Git-commit: 357285a2d1c06f0667c81e4dda35b92788b4f20c
Patch-mainline: v5.16-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

Originally drm_sched_job_init was the point of no return, after which
drivers really should submit a job. I've split that up, which allows
us to fix this issue pretty easily.

Only thing we have to take care of is to not skip to error paths after
that. Other drivers do this the same for out-fence and similar things.

v2: It's not really a bugfix, just an improvement, since all
drm_sched_job_arm does is reserve the fence number. And gaps should be
fine, as long as the drm_sched_job doesn't escape anywhere at all.

For robustness it's still better to align with other drivers here and
not bail out after job_arm().

v3: I misplaced drm_sched_job_arm by _one_ line! Thanks to Rob for
testing and debug help.

Cc: Rob Clark <robdclark@chromium.org>
Cc: Rob Clark <robdclark@gmail.com>
Tested-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Cc: Sean Paul <sean@poorly.run>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: linux-arm-msm@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: freedreno@lists.freedesktop.org
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210826093334.1117944-1-daniel.vetter@ffwll.ch
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/msm/msm_gem_submit.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
index 994a74c4b798..8fb79c14d44f 100644
--- a/drivers/gpu/drm/msm/msm_gem_submit.c
+++ b/drivers/gpu/drm/msm/msm_gem_submit.c
@@ -52,8 +52,6 @@ static struct msm_gem_submit *submit_create(struct drm_device *dev,
 		return ERR_PTR(ret);
 	}
 
-	drm_sched_job_arm(&job->base);
-
 	xa_init_flags(&submit->deps, XA_FLAGS_ALLOC);
 
 	kref_init(&submit->ref);
@@ -881,6 +879,8 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
 
 	submit->nr_cmds = i;
 
+	drm_sched_job_arm(&submit->base);
+
 	submit->user_fence = dma_fence_get(&submit->base.s_fence->finished);
 
 	/*
@@ -892,17 +892,16 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
 	if (submit->fence_id < 0) {
 		ret = submit->fence_id = 0;
 		submit->fence_id = 0;
-		goto out;
 	}
 
-	if (args->flags & MSM_SUBMIT_FENCE_FD_OUT) {
+	if (ret == 0 && args->flags & MSM_SUBMIT_FENCE_FD_OUT) {
 		struct sync_file *sync_file = sync_file_create(submit->user_fence);
 		if (!sync_file) {
 			ret = -ENOMEM;
-			goto out;
+		} else {
+			fd_install(out_fence_fd, sync_file->file);
+			args->fence_fd = out_fence_fd;
 		}
-		fd_install(out_fence_fd, sync_file->file);
-		args->fence_fd = out_fence_fd;
 	}
 
 	submit_attach_object_fences(submit);
-- 
2.38.1