dma_resv_wait_timeout returns greater than zero on success
as opposed to ttm_bo_wait_ctx. As a result of that relocs
will fail and give failure even when it was a success.
Signed-off-by: Tanmay Bhushan <[email protected]>
---
drivers/gpu/drm/nouveau/nouveau_gem.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c b/drivers/gpu/drm/nouveau/nouveau_gem.c
index f77e44958037..0e3690459144 100644
--- a/drivers/gpu/drm/nouveau/nouveau_gem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
@@ -706,9 +706,8 @@ nouveau_gem_pushbuf_reloc_apply(struct nouveau_cli *cli,
ret = dma_resv_wait_timeout(nvbo->bo.base.resv,
DMA_RESV_USAGE_BOOKKEEP,
false, 15 * HZ);
- if (ret == 0)
+ if (ret <= 0) {
ret = -EBUSY;
- if (ret) {
NV_PRINTK(err, cli, "reloc wait_idle failed: %ld\n",
ret);
break;
--
2.34.1
On 2023-01-19, Tanmay Bhushan <[email protected]> wrote:
> dma_resv_wait_timeout returns greater than zero on success
> as opposed to ttm_bo_wait_ctx. As a result of that relocs
> will fail and give failure even when it was a success.
Today I switched my workstation from 6.2 to 6.3-rc3 and started seeing
lots of new kernel messages:
[ 642.138313][ T1751] nouveau 0000:f0:10.0: X[1751]: reloc wait_idle failed: 1500
[ 642.138389][ T1751] nouveau 0000:f0:10.0: X[1751]: reloc apply: 1500
[ 646.123490][ T1751] nouveau 0000:f0:10.0: X[1751]: reloc wait_idle failed: 1500
[ 646.123573][ T1751] nouveau 0000:f0:10.0: X[1751]: reloc apply: 1500
The graphics seemed to go slower or hang a bit when these messages would
appear. I then found your patch! However, I have some comments about it.
First, it should include a fixes tag:
Fixes: 41d351f29528 ("drm/nouveau: stop using ttm_bo_wait")
> Signed-off-by: Tanmay Bhushan <[email protected]>
> ---
> drivers/gpu/drm/nouveau/nouveau_gem.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c b/drivers/gpu/drm/nouveau/nouveau_gem.c
> index f77e44958037..0e3690459144 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_gem.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
> @@ -706,9 +706,8 @@ nouveau_gem_pushbuf_reloc_apply(struct nouveau_cli *cli,
> ret = dma_resv_wait_timeout(nvbo->bo.base.resv,
> DMA_RESV_USAGE_BOOKKEEP,
> false, 15 * HZ);
> - if (ret == 0)
> + if (ret <= 0) {
> ret = -EBUSY;
This is incorrect for 2 reasons:
* it treats restarts as timeouts
* this function now returns >0 on success
> - if (ret) {
> NV_PRINTK(err, cli, "reloc wait_idle failed: %ld\n",
> ret);
> break;
I rearranged things to basically correctly translate the return code of
dma_resv_wait_timeout() to match the previous ttm_bo_wait():
ret = dma_resv_wait_timeout(nvbo->bo.base.resv,
DMA_RESV_USAGE_BOOKKEEP,
false, 15 * HZ);
if (ret == 0)
ret = -EBUSY;
if (ret > 0)
ret = 0;
if (ret) {
NV_PRINTK(err, cli, "reloc wait_idle failed: %ld\n",
ret);
break;
}
So the patch just becomes:
@@ -708,6 +708,8 @@ nouveau_gem_pushbuf_reloc_apply(struct n
false, 15 * HZ);
if (ret == 0)
ret = -EBUSY;
+ if (ret > 0)
+ ret = 0;
if (ret) {
NV_PRINTK(err, cli, "reloc wait_idle failed: %ld\n",
ret);
With this variant, everything runs correctly on my workstation again.
It probably deserves a comment about why @ret is being translated. Or
perhaps a new variable should be introduced to separate the return value
of dma_resv_wait_timeout() from the return value of this function.
Either way, this is an important fix for 6.3-rc!
John Ogness
Am 27.03.23 um 10:42 schrieb John Ogness:
> On 2023-01-19, Tanmay Bhushan <[email protected]> wrote:
>> dma_resv_wait_timeout returns greater than zero on success
>> as opposed to ttm_bo_wait_ctx. As a result of that relocs
>> will fail and give failure even when it was a success.
> Today I switched my workstation from 6.2 to 6.3-rc3 and started seeing
> lots of new kernel messages:
>
> [ 642.138313][ T1751] nouveau 0000:f0:10.0: X[1751]: reloc wait_idle failed: 1500
> [ 642.138389][ T1751] nouveau 0000:f0:10.0: X[1751]: reloc apply: 1500
> [ 646.123490][ T1751] nouveau 0000:f0:10.0: X[1751]: reloc wait_idle failed: 1500
> [ 646.123573][ T1751] nouveau 0000:f0:10.0: X[1751]: reloc apply: 1500
>
> The graphics seemed to go slower or hang a bit when these messages would
> appear. I then found your patch! However, I have some comments about it.
>
> First, it should include a fixes tag:
>
> Fixes: 41d351f29528 ("drm/nouveau: stop using ttm_bo_wait")
>
>> Signed-off-by: Tanmay Bhushan <[email protected]>
>> ---
>> drivers/gpu/drm/nouveau/nouveau_gem.c | 3 +--
>> 1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c b/drivers/gpu/drm/nouveau/nouveau_gem.c
>> index f77e44958037..0e3690459144 100644
>> --- a/drivers/gpu/drm/nouveau/nouveau_gem.c
>> +++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
>> @@ -706,9 +706,8 @@ nouveau_gem_pushbuf_reloc_apply(struct nouveau_cli *cli,
>> ret = dma_resv_wait_timeout(nvbo->bo.base.resv,
>> DMA_RESV_USAGE_BOOKKEEP,
>> false, 15 * HZ);
>> - if (ret == 0)
>> + if (ret <= 0) {
>> ret = -EBUSY;
> This is incorrect for 2 reasons:
>
> * it treats restarts as timeouts
>
> * this function now returns >0 on success
>
>> - if (ret) {
>> NV_PRINTK(err, cli, "reloc wait_idle failed: %ld\n",
>> ret);
>> break;
> I rearranged things to basically correctly translate the return code of
> dma_resv_wait_timeout() to match the previous ttm_bo_wait():
>
> ret = dma_resv_wait_timeout(nvbo->bo.base.resv,
> DMA_RESV_USAGE_BOOKKEEP,
> false, 15 * HZ);
> if (ret == 0)
> ret = -EBUSY;
> if (ret > 0)
> ret = 0;
> if (ret) {
> NV_PRINTK(err, cli, "reloc wait_idle failed: %ld\n",
> ret);
> break;
> }
>
> So the patch just becomes:
>
> @@ -708,6 +708,8 @@ nouveau_gem_pushbuf_reloc_apply(struct n
> false, 15 * HZ);
> if (ret == 0)
> ret = -EBUSY;
> + if (ret > 0)
> + ret = 0;
> if (ret) {
> NV_PRINTK(err, cli, "reloc wait_idle failed: %ld\n",
> ret);
>
> With this variant, everything runs correctly on my workstation again.
>
> It probably deserves a comment about why @ret is being translated. Or
> perhaps a new variable should be introduced to separate the return value
> of dma_resv_wait_timeout() from the return value of this function.
I'm going to take a look tomorrow, but your code already looks pretty
correct to me.
And sorry for the noise, missed the different in the conversion.
Thanks,
Christian.
>
> Either way, this is an important fix for 6.3-rc!
>
> John Ogness