[PATCH] drm/amd : Add HDP flush during jpeg init

[Alex Deucher]

On Thu, Aug 31, 2023 at 5:20 PM Timmy Tsai <timmtsai at amd.com> wrote:
>
> During jpeg init, CPU writes to frame buffer which can be cached by HDP,
> occasionally causing invalid header to be sent to MMSCH.  Perform HDP flush
> after writing to frame buffer before continuing with jpeg init sequence.
>
> Signed-off-by: Timmy Tsai <timmtsai at amd.com>
> ---
>  drivers/gpu/drm/amd/amdgpu/jpeg_v4_0.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/jpeg_v4_0.c b/drivers/gpu/drm/amd/amdgpu/jpeg_v4_0.c
> index 3eb3dcd56..27efba2da 100644
> --- a/drivers/gpu/drm/amd/amdgpu/jpeg_v4_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/jpeg_v4_0.c
> @@ -33,6 +33,7 @@
>  #include "vcn/vcn_4_0_0_offset.h"
>  #include "vcn/vcn_4_0_0_sh_mask.h"
>  #include "ivsrcid/vcn/irqsrcs_vcn_4_0.h"
> +#include "nbio/nbio_4_3_0_offset.h"
>
>  #define regUVD_JPEG_PITCH_INTERNAL_OFFSET                  0x401f
>
> @@ -468,6 +469,15 @@ static int jpeg_v4_0_start_sriov(struct amdgpu_device *adev)
>         table_loc = (uint32_t *)table->cpu_addr;
>         memcpy((void *)table_loc, &header, size);
>
> +       /* Perform HDP flush before writing to MMSCH registers */
> +       WREG32_SOC15(NBIO, 0, regBIF_BX_PF0_GPU_HDP_FLUSH_DONE, 0x0);
> +       WREG32_SOC15(NBIO, 0, regBIF_BX_PF0_GPU_HDP_FLUSH_REQ, 0xFFF);
> +       if (SOC15_WAIT_ON_RREG(NBIO, 0,
> +                       regBIF_BX_PF0_GPU_HDP_FLUSH_DONE, 0xFFF,
> +                       0xFFF)) {
> +               DRM_ERROR("Failed to flush HDP during jpeg init\n");
> +       }
> +

You can just call amdgpu_device_flush_hdp() here.

Alex


>         /* message MMSCH (in VCN[0]) to initialize this client
>          * 1, write to mmsch_vf_ctx_addr_lo/hi register with GPU mc addr
>          * of memory descriptor location
> --
> 2.34.1
>