[PATCH 1/3] drm/amdgpu: Add empty HDP flush function to JPEG v4.0.3

[Christian König]

Am 15.07.24 um 16:47 schrieb Jane Jian:
> From: Lijo Lazar <lijo.lazar at amd.com>
>
> JPEG v4.0.3 doesn't support HDP flush when RRMT is enabled. Instead,
> mmsch fw will do the flush.
>
> Signed-off-by: Lijo Lazar <lijo.lazar at amd.com>
> Signed-off-by: Jane Jian <Jane.Jian at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/jpeg_v4_0_3.c | 9 +++++++++
>   1 file changed, 9 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/jpeg_v4_0_3.c b/drivers/gpu/drm/amd/amdgpu/jpeg_v4_0_3.c
> index 04d8966423de..ea601047dab0 100644
> --- a/drivers/gpu/drm/amd/amdgpu/jpeg_v4_0_3.c
> +++ b/drivers/gpu/drm/amd/amdgpu/jpeg_v4_0_3.c
> @@ -621,6 +621,14 @@ static uint64_t jpeg_v4_0_3_dec_ring_get_wptr(struct amdgpu_ring *ring)
>   			ring->pipe ? (0x40 * ring->pipe - 0xc80) : 0);
>   }
>   
> +static void jpeg_v4_0_3_ring_emit_hdp_flush(struct amdgpu_ring *ring)
> +{
> +	/* VCN engine access for HDP flush doesn't work when RRMT is enabled.
> +	 * This is a workaround to avoid any HDP flush through VCN ring. Instead
> +	 * HDP flush will be done by driver while submitting doorbell.

I think that should read "HDP flush will be done by firmware ....".

Or is it really the driver which should do this? In this case the patch 
here would be wrong.

Regards,
Christian.

> +	 */
> +}
> +
>   /**
>    * jpeg_v4_0_3_dec_ring_set_wptr - set write pointer
>    *
> @@ -1072,6 +1080,7 @@ static const struct amdgpu_ring_funcs jpeg_v4_0_3_dec_ring_vm_funcs = {
>   	.emit_ib = jpeg_v4_0_3_dec_ring_emit_ib,
>   	.emit_fence = jpeg_v4_0_3_dec_ring_emit_fence,
>   	.emit_vm_flush = jpeg_v4_0_3_dec_ring_emit_vm_flush,
> +	.emit_hdp_flush = jpeg_v4_0_3_ring_emit_hdp_flush,
>   	.test_ring = amdgpu_jpeg_dec_ring_test_ring,
>   	.test_ib = amdgpu_jpeg_dec_ring_test_ib,
>   	.insert_nop = jpeg_v4_0_3_dec_ring_nop,