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On some controllers the pci latency timer
default value does not allow burst mode.
This patch fixes the latency value if it
is <= 0x80.
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
---
drivers/scsi/pata_artop.c | 7 +++++++
1 file changed, 7 insertions(+)
--- linux-ixp4xx.orig/drivers/scsi/pata_artop.c 2006-02-21 02:53:43.000000000 +0100
+++ linux-ixp4xx/drivers/scsi/pata_artop.c 2006-02-21 02:54:01.000000000 +0100
@@ -450,6 +450,13 @@ static int artop_init_one (struct pci_de
pci_read_config_byte(pdev, 0x49, ®);
pci_write_config_byte(pdev, 0x49, reg & ~ 0x30);
+ /* PCI latency must be > 0x80 for burst mode, tweak it
+ * if required.
+ */
+ pci_read_config_byte(pdev, PCI_LATENCY_TIMER, ®);
+ if (reg <= 0x80)
+ pci_write_config_byte(pdev, PCI_LATENCY_TIMER, 0x90);
+
/* Enable IRQ output and burst mode */
pci_read_config_byte(pdev, 0x4a, ®);
pci_write_config_byte(pdev, 0x4a, (reg & ~0x01) | 0x80);
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