[PATCH v3] drm/nouveau: fix incorrect conversion to dma_resv_wait_timeout()

From: John Ogness
Date: Fri Apr 14 2023 - 22:04:56 EST


Commit 41d351f29528 ("drm/nouveau: stop using ttm_bo_wait")
converted from ttm_bo_wait_ctx() to dma_resv_wait_timeout().
However, dma_resv_wait_timeout() returns greater than zero on
success as opposed to ttm_bo_wait_ctx(). As a result, relocs
will fail and log errors even when it was a success.

Change the return code handling to match that of
nouveau_gem_ioctl_cpu_prep(), which was already using
dma_resv_wait_timeout() correctly.

Fixes: 41d351f29528 ("drm/nouveau: stop using ttm_bo_wait")
Reported-by: Tanmay Bhushan <007047221b@xxxxxxxxx>
Link: https://lore.kernel.org/lkml/20230119225351.71657-1-007047221b@xxxxxxxxx
Signed-off-by: John Ogness <john.ogness@xxxxxxxxxxxxx>
---
I just realized that the nouveau driver style prefers to scope
variables used only in loops.

v3: Define @lret within the for-loop.

drivers/gpu/drm/nouveau/nouveau_gem.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c b/drivers/gpu/drm/nouveau/nouveau_gem.c
index f77e44958037..ab9062e50977 100644
--- a/drivers/gpu/drm/nouveau/nouveau_gem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
@@ -645,7 +645,7 @@ nouveau_gem_pushbuf_reloc_apply(struct nouveau_cli *cli,
struct drm_nouveau_gem_pushbuf_reloc *reloc,
struct drm_nouveau_gem_pushbuf_bo *bo)
{
- long ret = 0;
+ int ret = 0;
unsigned i;

for (i = 0; i < req->nr_relocs; i++) {
@@ -653,6 +653,7 @@ nouveau_gem_pushbuf_reloc_apply(struct nouveau_cli *cli,
struct drm_nouveau_gem_pushbuf_bo *b;
struct nouveau_bo *nvbo;
uint32_t data;
+ long lret;

if (unlikely(r->bo_index >= req->nr_buffers)) {
NV_PRINTK(err, cli, "reloc bo index invalid\n");
@@ -703,13 +704,18 @@ nouveau_gem_pushbuf_reloc_apply(struct nouveau_cli *cli,
data |= r->vor;
}

- ret = dma_resv_wait_timeout(nvbo->bo.base.resv,
- DMA_RESV_USAGE_BOOKKEEP,
- false, 15 * HZ);
- if (ret == 0)
+ lret = dma_resv_wait_timeout(nvbo->bo.base.resv,
+ DMA_RESV_USAGE_BOOKKEEP,
+ false, 15 * HZ);
+ if (!lret)
ret = -EBUSY;
+ else if (lret > 0)
+ ret = 0;
+ else
+ ret = lret;
+
if (ret) {
- NV_PRINTK(err, cli, "reloc wait_idle failed: %ld\n",
+ NV_PRINTK(err, cli, "reloc wait_idle failed: %d\n",
ret);
break;
}

base-commit: 09a9639e56c01c7a00d6c0ca63f4c7c41abe075d
--
2.30.2