[PATCH] drm/amd/pm: conditionally disable pcie lane switching for some sienna_cichlid SKUs

[Quan, Evan]

[AMD Official Use Only - General]

This seems able to address some audio noise issue observed per customer's feedback.

Evan
> -----Original Message-----
> From: Quan, Evan <Evan.Quan at amd.com>
> Sent: Friday, April 21, 2023 3:29 PM
> To: amd-gfx at lists.freedesktop.org
> Cc: Deucher, Alexander <Alexander.Deucher at amd.com>; Limonciello, Mario
> <Mario.Limonciello at amd.com>; Quan, Evan <Evan.Quan at amd.com>
> Subject: [PATCH] drm/amd/pm: conditionally disable pcie lane switching for
> some sienna_cichlid SKUs
> 
> Disable the pcie lane switching for some sienna_cichlid SKUs since it
> might not work well on some platforms.
> 
> Signed-off-by: Evan Quan <evan.quan at amd.com>
> Change-Id: Iea9ceaa146c8706768ee077c10e5d33bce9bc1c2
> ---
>  .../amd/pm/swsmu/smu11/sienna_cichlid_ppt.c   | 92 +++++++++++++++---
> -
>  1 file changed, 74 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu11/sienna_cichlid_ppt.c
> b/drivers/gpu/drm/amd/pm/swsmu/smu11/sienna_cichlid_ppt.c
> index 4b91cdc3eaa0..e7223513e384 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/smu11/sienna_cichlid_ppt.c
> +++ b/drivers/gpu/drm/amd/pm/swsmu/smu11/sienna_cichlid_ppt.c
> @@ -2067,33 +2067,94 @@ static int
> sienna_cichlid_display_disable_memory_clock_switch(struct smu_context
>  	return ret;
>  }
> 
> +static void sienna_cichlid_get_override_pcie_settings(struct smu_context
> *smu,
> +						      uint32_t
> *gen_speed_override,
> +						      uint32_t
> *lane_width_override)
> +{
> +	struct amdgpu_device *adev = smu->adev;
> +
> +	*gen_speed_override = 0xff;
> +	*lane_width_override = 0xff;
> +
> +	switch (adev->pdev->device) {
> +	case 0x73A0:
> +	case 0x73A1:
> +	case 0x73A2:
> +	case 0x73A3:
> +	case 0x73AB:
> +	case 0x73AE:
> +		/* Bit 7:0: PCIE lane width, 1 to 7 corresponds is x1 to x32 */
> +		*lane_width_override = 6;
> +		break;
> +	case 0x73E0:
> +	case 0x73E1:
> +	case 0x73E3:
> +		*lane_width_override = 4;
> +		break;
> +	case 0x7420:
> +	case 0x7421:
> +	case 0x7422:
> +	case 0x7423:
> +	case 0x7424:
> +		*lane_width_override = 3;
> +		break;
> +	default:
> +		break;
> +	}
> +}
> +
> +#define MAX(a, b)	((a) > (b) ? (a) : (b))
> +
>  static int sienna_cichlid_update_pcie_parameters(struct smu_context *smu,
>  					 uint32_t pcie_gen_cap,
>  					 uint32_t pcie_width_cap)
>  {
>  	struct smu_11_0_dpm_context *dpm_context = smu-
> >smu_dpm.dpm_context;
> -
> -	uint32_t smu_pcie_arg;
> +	struct smu_11_0_pcie_table *pcie_table = &dpm_context-
> >dpm_tables.pcie_table;
> +	uint32_t gen_speed_override, lane_width_override;
>  	uint8_t *table_member1, *table_member2;
> +	uint32_t min_gen_speed, max_gen_speed;
> +	uint32_t min_lane_width, max_lane_width;
> +	uint32_t smu_pcie_arg;
>  	int ret, i;
> 
>  	GET_PPTABLE_MEMBER(PcieGenSpeed, &table_member1);
>  	GET_PPTABLE_MEMBER(PcieLaneCount, &table_member2);
> 
> -	/* lclk dpm table setup */
> -	for (i = 0; i < MAX_PCIE_CONF; i++) {
> -		dpm_context->dpm_tables.pcie_table.pcie_gen[i] =
> table_member1[i];
> -		dpm_context->dpm_tables.pcie_table.pcie_lane[i] =
> table_member2[i];
> +	sienna_cichlid_get_override_pcie_settings(smu,
> +						  &gen_speed_override,
> +						  &lane_width_override);
> +
> +	/* PCIE gen speed override */
> +	if (gen_speed_override != 0xff) {
> +		min_gen_speed = MIN(pcie_gen_cap, gen_speed_override);
> +		max_gen_speed = MIN(pcie_gen_cap,
> gen_speed_override);
> +	} else {
> +		min_gen_speed = MAX(0, table_member1[0]);
> +		max_gen_speed = MIN(pcie_gen_cap, table_member1[1]);
> +		min_gen_speed = min_gen_speed > max_gen_speed ?
> +				max_gen_speed : min_gen_speed;
>  	}
> +	pcie_table->pcie_gen[0] = min_gen_speed;
> +	pcie_table->pcie_gen[1] = max_gen_speed;
> +
> +	/* PCIE lane width override */
> +	if (lane_width_override != 0xff) {
> +		min_lane_width = MIN(pcie_width_cap,
> lane_width_override);
> +		max_lane_width = MIN(pcie_width_cap,
> lane_width_override);
> +	} else {
> +		min_lane_width = MAX(1, table_member2[0]);
> +		max_lane_width = MIN(pcie_width_cap, table_member2[1]);
> +		min_lane_width = min_lane_width > max_lane_width ?
> +				 max_lane_width : min_lane_width;
> +	}
> +	pcie_table->pcie_lane[0] = min_lane_width;
> +	pcie_table->pcie_lane[1] = max_lane_width;
> 
>  	for (i = 0; i < NUM_LINK_LEVELS; i++) {
> -		smu_pcie_arg = (i << 16) |
> -			((table_member1[i] <= pcie_gen_cap) ?
> -			 (table_member1[i] << 8) :
> -			 (pcie_gen_cap << 8)) |
> -			((table_member2[i] <= pcie_width_cap) ?
> -			 table_member2[i] :
> -			 pcie_width_cap);
> +		smu_pcie_arg = (i << 16 |
> +				pcie_table->pcie_gen[i] << 8 |
> +				pcie_table->pcie_lane[i]);
> 
>  		ret = smu_cmn_send_smc_msg_with_param(smu,
>  				SMU_MSG_OverridePcieParameters,
> @@ -2101,11 +2162,6 @@ static int
> sienna_cichlid_update_pcie_parameters(struct smu_context *smu,
>  				NULL);
>  		if (ret)
>  			return ret;
> -
> -		if (table_member1[i] > pcie_gen_cap)
> -			dpm_context->dpm_tables.pcie_table.pcie_gen[i] =
> pcie_gen_cap;
> -		if (table_member2[i] > pcie_width_cap)
> -			dpm_context->dpm_tables.pcie_table.pcie_lane[i] =
> pcie_width_cap;
>  	}
> 
>  	return 0;
> --
> 2.34.1