Re: [PATCH] drm/amdgpu: remove mdelay in psp v12

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

Soft ping~

On Tue, Apr 22, 2025 at 12:16:29PM +0800, Huang Rui wrote:
> Since secure firmware is more stable than bring up phase, I believe we
> don't need such mdelays any more before wait PSP response on PSP v12.
> 
> Signed-off-by: Huang Rui <ray.huang@amd.com>
> ---
>  drivers/gpu/drm/amd/amdgpu/psp_v12_0.c | 16 ----------------
>  1 file changed, 16 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/psp_v12_0.c b/drivers/gpu/drm/amd/amdgpu/psp_v12_0.c
> index fcd708eae75c..6331941440d9 100644
> --- a/drivers/gpu/drm/amd/amdgpu/psp_v12_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/psp_v12_0.c
> @@ -99,9 +99,6 @@ static int psp_v12_0_bootloader_load_sysdrv(struct psp_context *psp)
>  	WREG32_SOC15(MP0, 0, mmMP0_SMN_C2PMSG_35,
>  	       psp_gfxdrv_command_reg);
>  
> -	/* there might be handshake issue with hardware which needs delay */
> -	mdelay(20);
> -
>  	ret = psp_wait_for(psp, SOC15_REG_OFFSET(MP0, 0, mmMP0_SMN_C2PMSG_35),
>  			   0x80000000, 0x80000000, false);
>  
> @@ -138,8 +135,6 @@ static int psp_v12_0_bootloader_load_sos(struct psp_context *psp)
>  	WREG32_SOC15(MP0, 0, mmMP0_SMN_C2PMSG_35,
>  	       psp_gfxdrv_command_reg);
>  
> -	/* there might be handshake issue with hardware which needs delay */
> -	mdelay(20);
>  	ret = psp_wait_for(psp, SOC15_REG_OFFSET(MP0, 0, mmMP0_SMN_C2PMSG_81),
>  			   RREG32_SOC15(MP0, 0, mmMP0_SMN_C2PMSG_81),
>  			   0, true);
> @@ -161,7 +156,6 @@ static void psp_v12_0_reroute_ih(struct psp_context *psp)
>  	WREG32_SOC15(MP0, 0, mmMP0_SMN_C2PMSG_70, tmp);
>  	WREG32_SOC15(MP0, 0, mmMP0_SMN_C2PMSG_64, GFX_CTRL_CMD_ID_GBR_IH_SET);
>  
> -	mdelay(20);
>  	psp_wait_for(psp, SOC15_REG_OFFSET(MP0, 0, mmMP0_SMN_C2PMSG_64),
>  		     0x80000000, 0x8000FFFF, false);
>  
> @@ -173,7 +167,6 @@ static void psp_v12_0_reroute_ih(struct psp_context *psp)
>  	WREG32_SOC15(MP0, 0, mmMP0_SMN_C2PMSG_70, tmp);
>  	WREG32_SOC15(MP0, 0, mmMP0_SMN_C2PMSG_64, GFX_CTRL_CMD_ID_GBR_IH_SET);
>  
> -	mdelay(20);
>  	psp_wait_for(psp, SOC15_REG_OFFSET(MP0, 0, mmMP0_SMN_C2PMSG_64),
>  		     0x80000000, 0x8000FFFF, false);
>  }
> @@ -200,9 +193,6 @@ static int psp_v12_0_ring_create(struct psp_context *psp,
>  		WREG32_SOC15(MP0, 0, mmMP0_SMN_C2PMSG_101,
>  					     GFX_CTRL_CMD_ID_INIT_GPCOM_RING);
>  
> -		/* there might be handshake issue with hardware which needs delay */
> -		mdelay(20);
> -
>  		/* Wait for response flag (bit 31) in C2PMSG_101 */
>  		ret = psp_wait_for(psp, SOC15_REG_OFFSET(MP0, 0, mmMP0_SMN_C2PMSG_101),
>  				   0x80000000, 0x8000FFFF, false);
> @@ -222,9 +212,6 @@ static int psp_v12_0_ring_create(struct psp_context *psp,
>  		psp_ring_reg = psp_ring_reg << 16;
>  		WREG32_SOC15(MP0, 0, mmMP0_SMN_C2PMSG_64, psp_ring_reg);
>  
> -		/* there might be handshake issue with hardware which needs delay */
> -		mdelay(20);
> -
>  		/* Wait for response flag (bit 31) in C2PMSG_64 */
>  		ret = psp_wait_for(psp, SOC15_REG_OFFSET(MP0, 0, mmMP0_SMN_C2PMSG_64),
>  				   0x80000000, 0x8000FFFF, false);
> @@ -247,9 +234,6 @@ static int psp_v12_0_ring_stop(struct psp_context *psp,
>  		WREG32_SOC15(MP0, 0, mmMP0_SMN_C2PMSG_64,
>  				     GFX_CTRL_CMD_ID_DESTROY_RINGS);
>  
> -	/* there might be handshake issue with hardware which needs delay */
> -	mdelay(20);
> -
>  	/* Wait for response flag (bit 31) */
>  	if (amdgpu_sriov_vf(adev))
>  		ret = psp_wait_for(psp, SOC15_REG_OFFSET(MP0, 0, mmMP0_SMN_C2PMSG_101),
> -- 
> 2.25.1
>