linux-kernel - Re: [PATCH] platform/x86: ISST: Optimize suspend/resume callbacks

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Message-ID: <daa60cbc-5266-374b-d5ee-8295a83764d3@linux.intel.com>
Date: Mon, 5 Jan 2026 17:15:47 +0200 (EET)
From: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
To: Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>
cc: Hans de Goede <hansg@...nel.org>, platform-driver-x86@...r.kernel.org, 
    LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] platform/x86: ISST: Optimize suspend/resume callbacks

On Mon, 29 Dec 2025, Srinivas Pandruvada wrote:

> If SST-CP or SST-PP is not supported then don't store configuration
> during suspend callback and restore during resume callback.
> 
> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>
> ---
>  .../x86/intel/speed_select_if/isst_tpmi_core.c  | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
> 
> diff --git a/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c b/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c
> index a624e0b2991f..5c4e1b4c0131 100644
> --- a/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c
> +++ b/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c
> @@ -1721,6 +1721,9 @@ void tpmi_sst_dev_remove(struct auxiliary_device *auxdev)
>  }
>  EXPORT_SYMBOL_NS_GPL(tpmi_sst_dev_remove, "INTEL_TPMI_SST");
>  
> +#define SST_PP_CAP_MASK_BIT_CP_ENABLE	0
> +#define SST_PP_CAP_MASK_BIT_PP_ENABLE	1
> +
>  void tpmi_sst_dev_suspend(struct auxiliary_device *auxdev)
>  {
>  	struct tpmi_sst_struct *tpmi_sst = auxiliary_get_drvdata(auxdev);
> @@ -1741,6 +1744,9 @@ void tpmi_sst_dev_suspend(struct auxiliary_device *auxdev)
>  		if (!pd_info || !pd_info->sst_base)
>  			continue;
>  
> +		if (!(pd_info->sst_header.cap_mask & BIT(SST_PP_CAP_MASK_BIT_CP_ENABLE)))

Please put BIT() directly in the defines.

-- 
 i.

> +			goto process_pp_suspend;
> +
>  		cp_base = pd_info->sst_base + pd_info->sst_header.cp_offset;
>  
>  		pd_info->saved_sst_cp_control = readq(cp_base + SST_CP_CONTROL_OFFSET);
> @@ -1749,6 +1755,10 @@ void tpmi_sst_dev_suspend(struct auxiliary_device *auxdev)
>  		memcpy_fromio(pd_info->saved_clos_assocs, cp_base + SST_CLOS_ASSOC_0_OFFSET,
>  			      sizeof(pd_info->saved_clos_assocs));
>  
> +process_pp_suspend:
> +		if (!(pd_info->sst_header.cap_mask & BIT(SST_PP_CAP_MASK_BIT_PP_ENABLE)))
> +			continue;
> +
>  		pd_info->saved_pp_control = readq(pd_info->sst_base +
>  						  pd_info->sst_header.pp_offset +
>  						  SST_PP_CONTROL_OFFSET);
> @@ -1776,6 +1786,9 @@ void tpmi_sst_dev_resume(struct auxiliary_device *auxdev)
>  		if (!pd_info || !pd_info->sst_base)
>  			continue;
>  
> +		if (!(pd_info->sst_header.cap_mask & BIT(SST_PP_CAP_MASK_BIT_CP_ENABLE)))
> +			goto process_pp_resume;
> +
>  		cp_base = pd_info->sst_base + pd_info->sst_header.cp_offset;
>  		writeq(pd_info->saved_sst_cp_control, cp_base + SST_CP_CONTROL_OFFSET);
>  		memcpy_toio(cp_base + SST_CLOS_CONFIG_0_OFFSET, pd_info->saved_clos_configs,
> @@ -1783,6 +1796,10 @@ void tpmi_sst_dev_resume(struct auxiliary_device *auxdev)
>  		memcpy_toio(cp_base + SST_CLOS_ASSOC_0_OFFSET, pd_info->saved_clos_assocs,
>  			    sizeof(pd_info->saved_clos_assocs));
>  
> +process_pp_resume:
> +		if (!(pd_info->sst_header.cap_mask & BIT(SST_PP_CAP_MASK_BIT_PP_ENABLE)))
> +			continue;
> +
>  		writeq(pd_info->saved_pp_control, power_domain_info->sst_base +
>  		       pd_info->sst_header.pp_offset + SST_PP_CONTROL_OFFSET);
>  	}
>