[PATCH v2 1/1] fpga: altera-cvp: Use pci_find_vsec_capability() when probing FPGA device

[PATCH v2 1/1] fpga: altera-cvp: Use pci_find_vsec_capability() when probing FPGA device

[Andy Shevchenko]

Currently altera_cvp_probe() open-codes pci_find_vsec_capability().
Refactor the former to use the latter. No functional change intended.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---

v2: removed unused variable (LKP)

 drivers/fpga/altera-cvp.c | 20 +++++---------------
 1 file changed, 5 insertions(+), 15 deletions(-)

diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
index 5af0bd33890c..514d2ac18e5f 100644
--- a/drivers/fpga/altera-cvp.c
+++ b/drivers/fpga/altera-cvp.c
@@ -22,9 +22,6 @@
 #define TIMEOUT_US	2000	/* CVP STATUS timeout for USERMODE polling */
 
 /* Vendor Specific Extended Capability Registers */
-#define VSE_PCIE_EXT_CAP_ID		0x0
-#define VSE_PCIE_EXT_CAP_ID_VAL		0x000b	/* 16bit */
-
 #define VSE_CVP_STATUS			0x1c	/* 32bit */
 #define VSE_CVP_STATUS_CFG_RDY		BIT(18)	/* CVP_CONFIG_READY */
 #define VSE_CVP_STATUS_CFG_ERR		BIT(19)	/* CVP_CONFIG_ERROR */
@@ -577,25 +574,18 @@ static int altera_cvp_probe(struct pci_dev *pdev,
 {
 	struct altera_cvp_conf *conf;
 	struct fpga_manager *mgr;
-	int ret, offset;
-	u16 cmd, val;
+	u16 cmd, offset;
 	u32 regval;
-
-	/* Discover the Vendor Specific Offset for this device */
-	offset = pci_find_next_ext_capability(pdev, 0, PCI_EXT_CAP_ID_VNDR);
-	if (!offset) {
-		dev_err(&pdev->dev, "No Vendor Specific Offset.\n");
-		return -ENODEV;
-	}
+	int ret;
 
 	/*
 	 * First check if this is the expected FPGA device. PCI config
 	 * space access works without enabling the PCI device, memory
 	 * space access is enabled further down.
 	 */
-	pci_read_config_word(pdev, offset + VSE_PCIE_EXT_CAP_ID, &val);
-	if (val != VSE_PCIE_EXT_CAP_ID_VAL) {
-		dev_err(&pdev->dev, "Wrong EXT_CAP_ID value 0x%x\n", val);
+	offset = pci_find_vsec_capability(pdev, PCI_VENDOR_ID_ALTERA, 0);
+	if (!offset) {
+		dev_err(&pdev->dev, "Wrong EXT_CAP_ID value\n");
 		return -ENODEV;
 	}
 
-- 
2.47.2

Re: [PATCH v2 1/1] fpga: altera-cvp: Use pci_find_vsec_capability() when probing FPGA device

[Andy Shevchenko]

On Fri, Jun 27, 2025 at 02:26:22PM +0300, Andy Shevchenko wrote:
> Currently altera_cvp_probe() open-codes pci_find_vsec_capability().
> Refactor the former to use the latter. No functional change intended.

Any comments, please?
Can it be applied now?

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v2 1/1] fpga: altera-cvp: Use pci_find_vsec_capability() when probing FPGA device

[Xu Yilun]

On Fri, Jun 27, 2025 at 02:26:22PM +0300, Andy Shevchenko wrote:
> Currently altera_cvp_probe() open-codes pci_find_vsec_capability().
> Refactor the former to use the latter. No functional change intended.
> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
> 
> v2: removed unused variable (LKP)
> 
>  drivers/fpga/altera-cvp.c | 20 +++++---------------
>  1 file changed, 5 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
> index 5af0bd33890c..514d2ac18e5f 100644
> --- a/drivers/fpga/altera-cvp.c
> +++ b/drivers/fpga/altera-cvp.c
> @@ -22,9 +22,6 @@
>  #define TIMEOUT_US	2000	/* CVP STATUS timeout for USERMODE polling */
>  
>  /* Vendor Specific Extended Capability Registers */
> -#define VSE_PCIE_EXT_CAP_ID		0x0
> -#define VSE_PCIE_EXT_CAP_ID_VAL		0x000b	/* 16bit */
> -
>  #define VSE_CVP_STATUS			0x1c	/* 32bit */
>  #define VSE_CVP_STATUS_CFG_RDY		BIT(18)	/* CVP_CONFIG_READY */
>  #define VSE_CVP_STATUS_CFG_ERR		BIT(19)	/* CVP_CONFIG_ERROR */
> @@ -577,25 +574,18 @@ static int altera_cvp_probe(struct pci_dev *pdev,
>  {
>  	struct altera_cvp_conf *conf;
>  	struct fpga_manager *mgr;
> -	int ret, offset;
> -	u16 cmd, val;
> +	u16 cmd, offset;
>  	u32 regval;
> -
> -	/* Discover the Vendor Specific Offset for this device */
> -	offset = pci_find_next_ext_capability(pdev, 0, PCI_EXT_CAP_ID_VNDR);
> -	if (!offset) {
> -		dev_err(&pdev->dev, "No Vendor Specific Offset.\n");
> -		return -ENODEV;
> -	}
> +	int ret;
>  
>  	/*
>  	 * First check if this is the expected FPGA device. PCI config
>  	 * space access works without enabling the PCI device, memory
>  	 * space access is enabled further down.
>  	 */
> -	pci_read_config_word(pdev, offset + VSE_PCIE_EXT_CAP_ID, &val);
> -	if (val != VSE_PCIE_EXT_CAP_ID_VAL) {
> -		dev_err(&pdev->dev, "Wrong EXT_CAP_ID value 0x%x\n", val);
> +	offset = pci_find_vsec_capability(pdev, PCI_VENDOR_ID_ALTERA, 0);

Mm.. the original code seems broken. It doesn't check the VSEC ID. And
you filled '0'. Is '0' specified in any SPEC? I didn't see it as a
wildcard.

Anyway, we should describe the change and remove "No functional change
intended".

> +	if (!offset) {
> +		dev_err(&pdev->dev, "Wrong EXT_CAP_ID value\n");

Should be "VSEC ID not found"

Thanks,
Yilun

>  		return -ENODEV;
>  	}
>  
> -- 
> 2.47.2
> 
>