From 9869a931c97fede539ccacc1724511f685ea6173 Mon Sep 17 00:00:00 2001
From: Chia-I Wu <olvaffe@gmail.com>
Date: Wed, 5 Feb 2020 10:19:46 -0800
Subject: drm/virtio: remove incorrect ENOSPC check
Git-commit: 1425a4ce4959d08d081e015fedfa4a76ba024c3a
Patch-mainline: v5.7-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322
The handling of virtqueue_add_sgs ENOSPC error is incorrect because
it can result in out-of-order virtqueue_add_sgs and break fences.
We never get ENOSPC anyway because the caller waits until there is
enough space (the other caller that did not wait was removed in
commit 32d6c2c5b522 ("drm/virtio: Rewrite virtio_gpu_queue_ctrl_buffer
using fenced version.")). Remove the incorrect and unnecessary error
path.
This also adds a WARN_ON(ret) until we properly handle errors.
Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
Cc: David Riley <davidriley@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20200205181955.202485-3-olvaffe@gmail.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/virtio/virtgpu_vq.c | 19 ++++++-------------
1 file changed, 6 insertions(+), 13 deletions(-)
diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c
index 301f47552aea..2b0a1ea1f7e0 100644
--- a/drivers/gpu/drm/virtio/virtgpu_vq.c
+++ b/drivers/gpu/drm/virtio/virtgpu_vq.c
@@ -310,8 +310,6 @@ static struct sg_table *vmalloc_to_sgt(char *data, uint32_t size, int *sg_ents)
static bool virtio_gpu_queue_ctrl_buffer_locked(struct virtio_gpu_device *vgdev,
struct virtio_gpu_vbuffer *vbuf,
struct scatterlist *vout)
- __releases(&vgdev->ctrlq.qlock)
- __acquires(&vgdev->ctrlq.qlock)
{
struct virtqueue *vq = vgdev->ctrlq.vq;
struct scatterlist *sgs[3], vcmd, vresp;
@@ -337,19 +335,14 @@ static bool virtio_gpu_queue_ctrl_buffer_locked(struct virtio_gpu_device *vgdev,
incnt++;
}
-retry:
ret = virtqueue_add_sgs(vq, sgs, outcnt, incnt, vbuf, GFP_ATOMIC);
- if (ret == -ENOSPC) {
- spin_unlock(&vgdev->ctrlq.qlock);
- wait_event(vgdev->ctrlq.ack_queue, vq->num_free >= outcnt + incnt);
- spin_lock(&vgdev->ctrlq.qlock);
- goto retry;
- } else {
- trace_virtio_gpu_cmd_queue(vq,
- (struct virtio_gpu_ctrl_hdr *)vbuf->buf);
+ WARN_ON(ret);
+
+ trace_virtio_gpu_cmd_queue(vq,
+ (struct virtio_gpu_ctrl_hdr *)vbuf->buf);
+
+ notify = virtqueue_kick_prepare(vq);
- notify = virtqueue_kick_prepare(vq);
- }
return notify;
}
--
2.28.0