Re: [PATCH] drm/amdgpu: Use correct VIEWPORT_DIMENSION for DCN2

[Huang Rui <ray.huang@amd.com>]

On Thu, Jan 06, 2022 at 04:39:01AM +0800, Harry Wentland wrote:
> For some reason this file isn't using the appropriate register
> headers for DCN headers, which means that on DCN2 we're getting
> the VIEWPORT_DIMENSION offset wrong.
> 
> This means that we're not correctly carving out the framebuffer
> memory correctly for a framebuffer allocated by EFI and
> therefore see corruption when loading amdgpu before the display
> driver takes over control of the framebuffer scanout.
> 
> Fix this by checking the DCE_HWIP and picking the correct offset
> accordingly.
> 
> Long-term we should expose this info from DC as GMC shouldn't
> need to know about DCN registers.
> 
> Signed-off-by: Harry Wentland <harry.wentland@amd.com>

Look good for me, this patch needs to backport it to stable kernel (CC
stable mailing list).

Reviewed-by: Huang Rui <ray.huang@amd.com>

> ---
>  drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
> index 57f2729a7bd0..8367ecf61af1 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
> @@ -72,6 +72,9 @@
>  #define mmDCHUBBUB_SDPIF_MMIO_CNTRL_0                                                                  0x049d
>  #define mmDCHUBBUB_SDPIF_MMIO_CNTRL_0_BASE_IDX                                                         2
>  
> +#define DCN2_mmHUBP0_DCSURF_PRI_VIEWPORT_DIMENSION                                                          0x05ea
> +#define DCN2_mmHUBP0_DCSURF_PRI_VIEWPORT_DIMENSION_BASE_IDX                                                 2
> +
>  
>  static const char *gfxhub_client_ids[] = {
>  	"CB",
> @@ -1142,7 +1145,6 @@ static unsigned gmc_v9_0_get_vbios_fb_size(struct amdgpu_device *adev)
>  		switch (adev->ip_versions[DCE_HWIP][0]) {
>  		case IP_VERSION(1, 0, 0):
>  		case IP_VERSION(1, 0, 1):
> -		case IP_VERSION(2, 1, 0):
>  			viewport = RREG32_SOC15(DCE, 0, mmHUBP0_DCSURF_PRI_VIEWPORT_DIMENSION);
>  			size = (REG_GET_FIELD(viewport,
>  					      HUBP0_DCSURF_PRI_VIEWPORT_DIMENSION, PRI_VIEWPORT_HEIGHT) *
> @@ -1150,6 +1152,14 @@ static unsigned gmc_v9_0_get_vbios_fb_size(struct amdgpu_device *adev)
>  					      HUBP0_DCSURF_PRI_VIEWPORT_DIMENSION, PRI_VIEWPORT_WIDTH) *
>  				4);
>  			break;
> +		case IP_VERSION(2, 1, 0):
> +			viewport = RREG32_SOC15(DCE, 0, DCN2_mmHUBP0_DCSURF_PRI_VIEWPORT_DIMENSION);
> +			size = (REG_GET_FIELD(viewport,
> +					      HUBP0_DCSURF_PRI_VIEWPORT_DIMENSION, PRI_VIEWPORT_HEIGHT) *
> +				REG_GET_FIELD(viewport,
> +					      HUBP0_DCSURF_PRI_VIEWPORT_DIMENSION, PRI_VIEWPORT_WIDTH) *
> +				4);
> +			break;
>  		default:
>  			viewport = RREG32_SOC15(DCE, 0, mmSCL0_VIEWPORT_SIZE);
>  			size = (REG_GET_FIELD(viewport, SCL0_VIEWPORT_SIZE, VIEWPORT_HEIGHT) *
> -- 
> 2.34.1
>