Re: [PATCH] i2c: amd-mp2: use msix/msi if the hardware supports

[Shyam Sundar S K <Shyam-sundar.S-k@amd.com>]

On 10/25/2022 11:41 PM, Raju Rangoju wrote:
> Use msix or msi interrupts if the hardware supports it. Else, fallback to
> legacy interrupts.
> 
> Fixes: 529766e0a011 ("i2c: Add drivers for the AMD PCIe MP2 I2C controller")
> Co-developed-by: Basavaraj Natikar <basavaraj.natikar@amd.com>
> Signed-off-by: Basavaraj Natikar <basavaraj.natikar@amd.com>
> Signed-off-by: Raju Rangoju <Raju.Rangoju@amd.com>

Looks good to me.

Acked-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>

> ---
>  drivers/i2c/busses/i2c-amd-mp2-pci.c | 30 +++++++++++++++++++---------
>  drivers/i2c/busses/i2c-amd-mp2.h     |  1 +
>  2 files changed, 22 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-amd-mp2-pci.c b/drivers/i2c/busses/i2c-amd-mp2-pci.c
> index f57077a7448d..143165300949 100644
> --- a/drivers/i2c/busses/i2c-amd-mp2-pci.c
> +++ b/drivers/i2c/busses/i2c-amd-mp2-pci.c
> @@ -288,7 +288,7 @@ static void amd_mp2_clear_reg(struct amd_mp2_dev *privdata)
>  static int amd_mp2_pci_init(struct amd_mp2_dev *privdata,
>  			    struct pci_dev *pci_dev)
>  {
> -	int rc;
> +	int irq_flag = 0, rc;
>  
>  	pci_set_drvdata(pci_dev, privdata);
>  
> @@ -311,17 +311,29 @@ static int amd_mp2_pci_init(struct amd_mp2_dev *privdata,
>  	if (rc)
>  		goto err_dma_mask;
>  
> -	/* Set up intx irq */
> +	/* request and enable interrupt */
>  	writel(0, privdata->mmio + AMD_P2C_MSG_INTEN);
> -	pci_intx(pci_dev, 1);
> -	rc = devm_request_irq(&pci_dev->dev, pci_dev->irq, amd_mp2_irq_isr,
> -			      IRQF_SHARED, dev_name(&pci_dev->dev), privdata);
> -	if (rc)
> -		pci_err(pci_dev, "Failure requesting irq %i: %d\n",
> -			pci_dev->irq, rc);
> +	rc = pci_alloc_irq_vectors(pci_dev, 1, 1, PCI_IRQ_ALL_TYPES);
> +	if (rc < 0) {
> +		dev_err(&pci_dev->dev, "Failed to allocate single IRQ err=%d\n", rc);
> +		goto err_dma_mask;
> +	}
> +
> +	privdata->dev_irq = pci_irq_vector(pci_dev, 0);
> +	if (!pci_dev->msix_enabled && !pci_dev->msi_enabled)
> +		irq_flag = IRQF_SHARED;
> +
> +	rc = devm_request_irq(&pci_dev->dev, privdata->dev_irq,
> +			      amd_mp2_irq_isr, irq_flag, dev_name(&pci_dev->dev), privdata);
> +	if (rc) {
> +		pci_err(pci_dev, "Failure requesting irq %i: %d\n", privdata->dev_irq, rc);
> +		goto free_irq_vectors;
> +	}
>  
>  	return rc;
>  
> +free_irq_vectors:
> +	free_irq(privdata->dev_irq, privdata);
>  err_dma_mask:
>  	pci_clear_master(pci_dev);
>  err_pci_enable:
> @@ -364,7 +376,7 @@ static void amd_mp2_pci_remove(struct pci_dev *pci_dev)
>  	pm_runtime_forbid(&pci_dev->dev);
>  	pm_runtime_get_noresume(&pci_dev->dev);
>  
> -	pci_intx(pci_dev, 0);
> +	free_irq(privdata->dev_irq, privdata);
>  	pci_clear_master(pci_dev);
>  
>  	amd_mp2_clear_reg(privdata);
> diff --git a/drivers/i2c/busses/i2c-amd-mp2.h b/drivers/i2c/busses/i2c-amd-mp2.h
> index ddecd0c88656..018a42de8b1e 100644
> --- a/drivers/i2c/busses/i2c-amd-mp2.h
> +++ b/drivers/i2c/busses/i2c-amd-mp2.h
> @@ -183,6 +183,7 @@ struct amd_mp2_dev {
>  	struct mutex c2p_lock;
>  	u8 c2p_lock_busid;
>  	unsigned int probed;
> +	int dev_irq;
>  };
>  
>  /* PCIe communication driver */
>