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

From: Robert Hancock
Date: Wed Aug 05 2009 - 19:33:49 EST


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@xxxxxxxx>

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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