[PATCH] libata: ata_piix 450NX errata

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

1 files changed, 43 insertions, 1 deletions

diff --git a/drivers/scsi/ata_piix.c b/drivers/scsi/ata_piix.c
index 908ff1f9671a..0ea27873b9ff 100644
--- a/drivers/scsi/ata_piix.c
+++ b/drivers/scsi/ata_piix.c
@@ -620,6 +620,40 @@ static int piix_disable_ahci(struct pci_dev *pdev)
 }
 
 /**
+ *      piix_check_450nx_errata -       Check for problem 450NX setup
+ *      
+ *      Check for the present of 450NX errata #19 and errata #25. If
+ *      they are found return an error code so we can turn off DMA
+ */
+
+static int __devinit piix_check_450nx_errata(struct pci_dev *ata_dev)
+{
+        struct pci_dev *pdev = NULL;
+        u16 cfg;
+        u8 rev;
+        int no_piix_dma = 0;
+        
+        while((pdev = pci_get_device(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82454NX, pdev)) != NULL)
+        {
+                /* Look for 450NX PXB. Check for problem configurations
+                   A PCI quirk checks bit 6 already */
+                pci_read_config_byte(pdev, PCI_REVISION_ID, &rev);
+                pci_read_config_word(pdev, 0x41, &cfg);
+                /* Only on the original revision: IDE DMA can hang */
+                if(rev == 0x00)
+                        no_piix_dma = 1;
+                /* On all revisions below 5 PXB bus lock must be disabled for IDE */
+                else if(cfg & (1<<14) && rev < 5)
+                        no_piix_dma = 2;
+        }
+        if(no_piix_dma)
+                dev_printk(KERN_WARNING, &ata_dev->dev, "450NX errata present, disabling IDE DMA.\n");
+        if(no_piix_dma == 2)
+                dev_printk(KERN_WARNING, &ata_dev->dev, "A BIOS update may resolve this.\n");
+        return no_piix_dma;
+}               
+
+/**
  *      piix_init_one - Register PIIX ATA PCI device with kernel services
  *      @pdev: PCI device to register
  *      @ent: Entry in piix_pci_tbl matching with @pdev
@@ -693,7 +727,15 @@ static int piix_init_one (struct pci_dev *pdev, const struct pci_device_id *ent)
                            "combined mode detected (p=%u, s=%u)\n",
                            pata_chan, sata_chan);
         }
-
+        if (piix_check_450nx_errata(pdev)) {
+                /* This writes into the master table but it does not
+                   really matter for this errata as we will apply it to
+                   all the PIIX devices on the board */
+                port_info[0]->mwdma_mask = 0;
+                port_info[0]->udma_mask = 0;
+                port_info[1]->mwdma_mask = 0;
+                port_info[1]->udma_mask = 0;
+        }
         return ata_pci_init_one(pdev, port_info, 2);
 }