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| author | Nate Dailey <nate.dailey@stratus.com> | 2007-02-15 18:13:46 -0500 |
|---|---|---|
| committer | Jeff Garzik <jeff@garzik.org> | 2007-02-15 18:13:46 -0500 |
| commit | 7de970e11fb832a56c897276967fb0e49f59b313 (patch) | |
| tree | 6e49d7e80c9b3f847a3d6bd84ccbf70614a2ef1d | |
| parent | 5278b50cea851d8264b7b28212a483328650476f (diff) | |
| download | linux-stable-7de970e11fb832a56c897276967fb0e49f59b313.tar.gz linux-stable-7de970e11fb832a56c897276967fb0e49f59b313.tar.bz2 linux-stable-7de970e11fb832a56c897276967fb0e49f59b313.zip | |
sata_vsc: use default cache line size if non-zero
This modifies drivers/ata/sata_vsc.c to only set the cache line size
to 0x80 if the default value is zero. Apparently zero isn't allowed
due to a bug in the chip, but I've found performance is much better
with the (non-zero) default instead of 0x80.
[note1: "default" means BIOS-programmed value, in this context -jgarzik]
[note2: superfluous braces were removed from the patch -jg]
Signed-off-by: Nate Dailey <nate.dailey@stratus.com>
Signed-off-by: Jeremy Higdon <jeremy@sgi.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
| -rw-r--r-- | drivers/ata/sata_vsc.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/ata/sata_vsc.c b/drivers/ata/sata_vsc.c index 3d9daf231115..2fd037bde090 100644 --- a/drivers/ata/sata_vsc.c +++ b/drivers/ata/sata_vsc.c @@ -346,6 +346,7 @@ static int __devinit vsc_sata_init_one (struct pci_dev *pdev, const struct pci_d struct ata_probe_ent *probe_ent; void __iomem *mmio_base; int rc; + u8 cls; if (!printed_version++) dev_printk(KERN_DEBUG, &pdev->dev, "version " DRV_VERSION "\n"); @@ -383,9 +384,12 @@ static int __devinit vsc_sata_init_one (struct pci_dev *pdev, const struct pci_d INIT_LIST_HEAD(&probe_ent->node); /* - * Due to a bug in the chip, the default cache line size can't be used + * Due to a bug in the chip, the default cache line size can't be + * used (unless the default is non-zero). */ - pci_write_config_byte(pdev, PCI_CACHE_LINE_SIZE, 0x80); + pci_read_config_byte(pdev, PCI_CACHE_LINE_SIZE, &cls); + if (cls == 0x00) + pci_write_config_byte(pdev, PCI_CACHE_LINE_SIZE, 0x80); if (pci_enable_msi(pdev) == 0) pci_intx(pdev, 0); |