linux-kernel - Re: [PATCH 2/3] platform/x86/intel/pmc/lnl: Remove SSRAM support

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Message-ID: <98369369-9569-4c7a-8827-269fcc71a3de@linux.intel.com>
Date: Thu, 22 Feb 2024 19:06:01 -0800
From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@...ux.intel.com>
To: "David E. Box" <david.e.box@...ux.intel.com>,
 rajvi.jingar@...ux.intel.com, platform-driver-x86@...r.kernel.org,
 linux-kernel@...r.kernel.org, hdegoede@...hat.com,
 ilpo.jarvinen@...ux.intel.com
Subject: Re: [PATCH 2/3] platform/x86/intel/pmc/lnl: Remove SSRAM support


On 2/21/24 1:12 PM, David E. Box wrote:
> A recent PMC firmware change in Lunar Lake caused the pmc_core driver to
> fail to probe. This is due to a change in the GUID for PMC telemetry
> coming from the SSRAM device. We are told the current update may change
> again before a final release so we can't upstream a fix just yet. In the
> meantime, remove SSRAM support for Lunar Lake so the driver can load and
> provide some basic functionality.

I would remove usage of "We" and just comment that that the value
is expected to change again. So disable the support till it is finalized.

>
> Fixes: 3748dfdae2a6 ("platform/x86/intel/pmc: Add Lunar Lake M support to intel_pmc_core driver")
> Signed-off-by: David E. Box <david.e.box@...ux.intel.com>
> ---

Change looks fine to me.

Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@...ux.intel.com>
>  drivers/platform/x86/intel/pmc/lnl.c | 38 +++-------------------------
>  1 file changed, 4 insertions(+), 34 deletions(-)
>
> diff --git a/drivers/platform/x86/intel/pmc/lnl.c b/drivers/platform/x86/intel/pmc/lnl.c
> index abad17cdd3d7..068d72504683 100644
> --- a/drivers/platform/x86/intel/pmc/lnl.c
> +++ b/drivers/platform/x86/intel/pmc/lnl.c
> @@ -13,21 +13,6 @@
>  
>  #include "core.h"
>  
> -#define SOCM_LPM_REQ_GUID	0x11594920
> -
> -#define PMC_DEVID_SOCM	0xa87f
> -
> -static const u8 LNL_LPM_REG_INDEX[] = {0, 4, 5, 6, 8, 9, 10, 11, 12, 13, 14, 15, 16, 20};
> -
> -static struct pmc_info lnl_pmc_info_list[] = {
> -	{
> -		.guid	= SOCM_LPM_REQ_GUID,
> -		.devid	= PMC_DEVID_SOCM,
> -		.map	= &lnl_socm_reg_map,
> -	},
> -	{}
> -};
> -
>  const struct pmc_bit_map lnl_ltr_show_map[] = {
>  	{"SOUTHPORT_A",		CNP_PMC_LTR_SPA},
>  	{"SOUTHPORT_B",		CNP_PMC_LTR_SPB},
> @@ -490,7 +475,6 @@ const struct pmc_reg_map lnl_socm_reg_map = {
>  	.lpm_sts = lnl_lpm_maps,
>  	.lpm_status_offset = MTL_LPM_STATUS_OFFSET,
>  	.lpm_live_status_offset = MTL_LPM_LIVE_STATUS_OFFSET,
> -	.lpm_reg_index = LNL_LPM_REG_INDEX,
>  };
>  
>  #define LNL_NPU_PCI_DEV		0x643e
> @@ -517,33 +501,19 @@ static int lnl_resume(struct pmc_dev *pmcdev)
>  int lnl_core_init(struct pmc_dev *pmcdev)
>  {
>  	int ret;
> -	int func = 2;
> -	bool ssram_init = true;
>  	struct pmc *pmc = pmcdev->pmcs[PMC_IDX_SOC];
>  
>  	lnl_d3_fixup();
>  
>  	pmcdev->suspend = cnl_suspend;
>  	pmcdev->resume = lnl_resume;
> -	pmcdev->regmap_list = lnl_pmc_info_list;
> -	ret = pmc_core_ssram_init(pmcdev, func);
>  
> -	/* If regbase not assigned, set map and discover using legacy method */
> -	if (ret) {
> -		ssram_init = false;
> -		pmc->map = &lnl_socm_reg_map;
> -		ret = get_primary_reg_base(pmc);
> -		if (ret)
> -			return ret;
> -	}
> +	pmc->map = &lnl_socm_reg_map;
> +	ret = get_primary_reg_base(pmc);
> +	if (ret)
> +		return ret;
>  
>  	pmc_core_get_low_power_modes(pmcdev);
>  
> -	if (ssram_init) {
> -		ret = pmc_core_ssram_get_lpm_reqs(pmcdev);
> -		if (ret)
> -			return ret;
> -	}
> -
>  	return 0;
>  }

-- 
Sathyanarayanan Kuppuswamy
Linux Kernel Developer