[PATCH 21/22] platform/x86/intel/pmc/ssram: Make PMT registration optional

David E. Box posted 22 patches 3 weeks, 4 days ago
[PATCH 21/22] platform/x86/intel/pmc/ssram: Make PMT registration optional
Posted by David E. Box 3 weeks, 4 days ago
The SSRAM telemetry driver extracts essential PMC device ID and power
management base address information that intel_pmc_core depends on for core
functionality. PMT registration failure should not prevent this critical
data from being available, as it would break intel_pmc_core operation
entirely.

Change the behavior to log a warning when PMT registration fails but
continue with successful driver initialization, ensuring the primary
telemetry data remains accessible to dependent drivers.

Signed-off-by: David E. Box <david.e.box@linux.intel.com>
---
 drivers/platform/x86/intel/pmc/ssram_telemetry.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/platform/x86/intel/pmc/ssram_telemetry.c b/drivers/platform/x86/intel/pmc/ssram_telemetry.c
index b937ebb2322f..12b7c1299c2f 100644
--- a/drivers/platform/x86/intel/pmc/ssram_telemetry.c
+++ b/drivers/platform/x86/intel/pmc/ssram_telemetry.c
@@ -106,6 +106,7 @@ pmc_ssram_telemetry_get_pmc_pci(struct pci_dev *pcidev, unsigned int pmc_idx, u3
 	void __iomem __free(pmc_ssram_telemetry_iounmap) *tmp_ssram = NULL;
 	void __iomem __free(pmc_ssram_telemetry_iounmap) *ssram = NULL;
 	u64 ssram_base;
+	int ret;
 
 	ssram_base = pci_resource_start(pcidev, 0);
 	tmp_ssram = ioremap(ssram_base, SSRAM_HDR_SIZE);
@@ -133,7 +134,11 @@ pmc_ssram_telemetry_get_pmc_pci(struct pci_dev *pcidev, unsigned int pmc_idx, u3
 	pmc_ssram_get_devid_pwrmbase(ssram, pmc_idx);
 
 	/* Find and register and PMC telemetry entries */
-	return pmc_ssram_telemetry_add_pmt(pcidev, ssram_base, ssram);
+	ret = pmc_ssram_telemetry_add_pmt(pcidev, ssram_base, ssram);
+	if (ret)
+		dev_warn(&pcidev->dev, "could not register PMT\n");
+
+	return 0;
 }
 
 static int pmc_ssram_telemetry_pci_init(struct pci_dev *pcidev)
@@ -208,12 +213,12 @@ static int pmc_ssram_telemetry_acpi_init(struct pci_dev *pcidev,
 
 	ret = intel_vsec_register(&pcidev->dev, &info);
 	if (ret)
-		goto cleanup_acpi_disc;
+		dev_warn(&pcidev->dev, "could not register PMT\n");
 
 	ret = pmc_ssram_telemetry_get_pmc_acpi(pcidev, index);
 
-cleanup_acpi_disc:
 	kfree(acpi_disc);
+
 cleanup_acpi_buf:
 	ACPI_FREE(buf.pointer);
 
-- 
2.43.0
Re: [PATCH 21/22] platform/x86/intel/pmc/ssram: Make PMT registration optional
Posted by Ilpo Järvinen 2 weeks, 6 days ago
On Thu, 12 Mar 2026, David E. Box wrote:

> The SSRAM telemetry driver extracts essential PMC device ID and power
> management base address information that intel_pmc_core depends on for core
> functionality. PMT registration failure should not prevent this critical
> data from being available, as it would break intel_pmc_core operation

Are you missing a "not" here? I find the entire sentence hard to 
understand.

> entirely.
> 
> Change the behavior to log a warning when PMT registration fails but
> continue with successful driver initialization, ensuring the primary
> telemetry data remains accessible to dependent drivers.
> 
> Signed-off-by: David E. Box <david.e.box@linux.intel.com>
> ---
>  drivers/platform/x86/intel/pmc/ssram_telemetry.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/platform/x86/intel/pmc/ssram_telemetry.c b/drivers/platform/x86/intel/pmc/ssram_telemetry.c
> index b937ebb2322f..12b7c1299c2f 100644
> --- a/drivers/platform/x86/intel/pmc/ssram_telemetry.c
> +++ b/drivers/platform/x86/intel/pmc/ssram_telemetry.c
> @@ -106,6 +106,7 @@ pmc_ssram_telemetry_get_pmc_pci(struct pci_dev *pcidev, unsigned int pmc_idx, u3
>  	void __iomem __free(pmc_ssram_telemetry_iounmap) *tmp_ssram = NULL;
>  	void __iomem __free(pmc_ssram_telemetry_iounmap) *ssram = NULL;
>  	u64 ssram_base;
> +	int ret;
>  
>  	ssram_base = pci_resource_start(pcidev, 0);
>  	tmp_ssram = ioremap(ssram_base, SSRAM_HDR_SIZE);
> @@ -133,7 +134,11 @@ pmc_ssram_telemetry_get_pmc_pci(struct pci_dev *pcidev, unsigned int pmc_idx, u3
>  	pmc_ssram_get_devid_pwrmbase(ssram, pmc_idx);
>  
>  	/* Find and register and PMC telemetry entries */
> -	return pmc_ssram_telemetry_add_pmt(pcidev, ssram_base, ssram);
> +	ret = pmc_ssram_telemetry_add_pmt(pcidev, ssram_base, ssram);
> +	if (ret)
> +		dev_warn(&pcidev->dev, "could not register PMT\n");
> +
> +	return 0;
>  }
>  
>  static int pmc_ssram_telemetry_pci_init(struct pci_dev *pcidev)
> @@ -208,12 +213,12 @@ static int pmc_ssram_telemetry_acpi_init(struct pci_dev *pcidev,
>  
>  	ret = intel_vsec_register(&pcidev->dev, &info);
>  	if (ret)
> -		goto cleanup_acpi_disc;
> +		dev_warn(&pcidev->dev, "could not register PMT\n");
>  
>  	ret = pmc_ssram_telemetry_get_pmc_acpi(pcidev, index);
>  
> -cleanup_acpi_disc:
>  	kfree(acpi_disc);
> +
>  cleanup_acpi_buf:
>  	ACPI_FREE(buf.pointer);
>  
> 

-- 
 i.