Re: [PATCH 2.6.32 v2] MCP55 SATA2 conditional MSI support for sata_nv

[Robert Hancock <hancockrwd@gmail.com>]

On 08/05/2009 01:20 PM, Tony Vroon wrote:
> The nVidia MCP55 SATA2 controller quite happily supports MSI.
> This adds an option to use it. It is disabled by default and
> will only be honoured on the specific controller I tested.
> This was suggested in 2007 back when the driver was less mature,
> perhaps now is a better time for it.

I'm not sure the conditional on MCP55 is necessary, I would be inclined 
to just try to enable it on any device if the option is specified. 
pci_enable_msi will just fail harmlessly if the device doesn't support 
MSI capability or the kernel detects MSI is not usable on the machine 
(which these days I think we should be able to do fairly accurately on 
HT chipsets..)

>
> Signed-off-by: Tony Vroon<tony@linx.net>
>
> diff --git a/drivers/ata/sata_nv.c b/drivers/ata/sata_nv.c
> index b2d11f3..5ec29c4 100644
> --- a/drivers/ata/sata_nv.c
> +++ b/drivers/ata/sata_nv.c
> @@ -602,6 +602,7 @@ MODULE_VERSION(DRV_VERSION);
>
>   static int adma_enabled;
>   static int swncq_enabled = 1;
> +static int msi_enabled;
>
>   static void nv_adma_register_mode(struct ata_port *ap)
>   {
> @@ -2459,6 +2460,13 @@ static int nv_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
>   	} else if (type == SWNCQ)
>   		nv_swncq_host_init(host);
>
> +	/* enable MSI if requested */
> +	if (pdev->device == PCI_DEVICE_ID_NVIDIA_NFORCE_MCP55_SATA2&&
> +		msi_enabled) {
> +		dev_printk(KERN_NOTICE,&pdev->dev, "Using MSI\n");
> +		pci_enable_msi(pdev);
> +	}
> +
>   	pci_set_master(pdev);
>   	return ata_host_activate(host, pdev->irq, ipriv->irq_handler,
>   				 IRQF_SHARED, ipriv->sht);
> @@ -2558,4 +2566,6 @@ module_param_named(adma, adma_enabled, bool, 0444);
>   MODULE_PARM_DESC(adma, "Enable use of ADMA (Default: false)");
>   module_param_named(swncq, swncq_enabled, bool, 0444);
>   MODULE_PARM_DESC(swncq, "Enable use of SWNCQ (Default: true)");
> +module_param_named(msi, msi_enabled, bool, 0444);
> +MODULE_PARM_DESC(msi, "Enable use of MSI (Default: false)");
>
> --
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