Re: [PATCH 3/4] dma-buf: Add callback and enable signaling on debug

Christian König
2022-09-05T11:27:02Z

Am 05.09.22 um 12:56 schrieb Arvind Yadav:
> Here's on debug adding an enable_signaling callback for the stub
> fences and enabling software signaling for the stub fence which
> is always signaled. This fence should enable software signaling
> otherwise the AMD GPU scheduler will cause a GPU reset due to a
> GPU scheduler cleanup activity timeout.
>
> Signed-off-by: Arvind Yadav <Arvind.Yadav@amd.com>
> ---
> drivers/dma-buf/dma-fence.c | 17 +++++++++++++++++
> 1 file changed, 17 insertions(+)
>
> diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
> index 066400ed8841..0a67af945ef8 100644
> --- a/drivers/dma-buf/dma-fence.c
> +++ b/drivers/dma-buf/dma-fence.c
> @@ -27,6 +27,10 @@ EXPORT_TRACEPOINT_SYMBOL(dma_fence_signaled);
> static DEFINE_SPINLOCK(dma_fence_stub_lock);
> static struct dma_fence dma_fence_stub;
>
> +#ifdef CONFIG_DEBUG_FS
> +static bool __dma_fence_enable_signaling(struct dma_fence *fence);
> +#endif
> +
> /*
> * fence context counter: each execution context should have its own
> * fence context, this allows checking if fences belong to the same
> @@ -116,9 +120,19 @@ static const char *dma_fence_stub_get_name(struct dma_fence *fence)
> return "stub";
> }
>
> +#ifdef CONFIG_DEBUG_FS
> +static bool dma_fence_stub_enable_signaling(struct dma_fence *f)
> +{
> + return true;
> +}
> +#endif

Again, adding the callback is unnecessary.

> +
> static const struct dma_fence_ops dma_fence_stub_ops = {
> .get_driver_name = dma_fence_stub_get_name,
> .get_timeline_name = dma_fence_stub_get_name,
> +#ifdef CONFIG_DEBUG_FS
> + .enable_signaling = dma_fence_stub_enable_signaling,
> +#endif
> };
>
> /**
> @@ -136,6 +150,9 @@ struct dma_fence *dma_fence_get_stub(void)
> &dma_fence_stub_ops,
> &dma_fence_stub_lock,
> 0, 0);
> +#ifdef CONFIG_DEBUG_FS
> + __dma_fence_enable_signaling(&dma_fence_stub);
> +#endif
> dma_fence_signal_locked(&dma_fence_stub);
> }
> spin_unlock(&dma_fence_stub_lock);