[PATCH] pata_rz1000: Force readahead off on resume

The RZ1000 is a generic device except that it has a readahead fifo flaw
that corrupts. We force this off at init time but we want to be paranoid
and force it off at resume as well. I don't know of any actual hardware
that supports both RZ1000 and suspend to RAM but given its a disk muncher
better safe than sorry.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

diff --git a/drivers/ata/pata_rz1000.c b/drivers/ata/pata_rz1000.c
index e4e5ea423fef2f5d2f7af3fee3d0cd4bba4e2688..21567aba82d24d2f0a2c8cd4671148e9e4982850 100644 (file)
--- a/drivers/ata/pata_rz1000.c
+++ b/drivers/ata/pata_rz1000.c
@@ -21,7 +21,7 @@
 #include <linux/libata.h>
 
 #define DRV_NAME       "pata_rz1000"
-#define DRV_VERSION    "0.2.2"
+#define DRV_VERSION    "0.2.3"
 
 
 /**
@@ -92,6 +92,8 @@ static struct scsi_host_template rz1000_sht = {
        .slave_configure        = ata_scsi_slave_config,
        .slave_destroy          = ata_scsi_slave_destroy,
        .bios_param             = ata_std_bios_param,
+       .resume                 = ata_scsi_device_resume,
+       .suspend                = ata_scsi_device_suspend,
 };
 
 static struct ata_port_operations rz1000_port_ops = {
@@ -129,6 +131,19 @@ static struct ata_port_operations rz1000_port_ops = {
        .host_stop      = ata_host_stop
 };
 
+static int rz1000_fifo_disable(struct pci_dev *pdev)
+{
+       u16 reg;
+       /* Be exceptionally paranoid as we must be sure to apply the fix */
+       if (pci_read_config_word(pdev, 0x40, &reg) != 0)
+               return -1;
+       reg &= 0xDFFF;
+       if (pci_write_config_word(pdev, 0x40, reg) != 0)
+               return -1;
+       printk(KERN_INFO DRV_NAME ": disabled chipset readahead.\n");
+       return 0;
+}
+
 /**
  *     rz1000_init_one - Register RZ1000 ATA PCI device with kernel services
  *     @pdev: PCI device to register
@@ -143,7 +158,6 @@ static int rz1000_init_one (struct pci_dev *pdev, const struct pci_device_id *en
 {
        static int printed_version;
        struct ata_port_info *port_info[2];
-       u16 reg;
        static struct ata_port_info info = {
                .sht = &rz1000_sht,
                .flags = ATA_FLAG_SLAVE_POSS | ATA_FLAG_SRST,
@@ -154,23 +168,25 @@ static int rz1000_init_one (struct pci_dev *pdev, const struct pci_device_id *en
        if (!printed_version++)
                printk(KERN_DEBUG DRV_NAME " version " DRV_VERSION "\n");
 
-       /* Be exceptionally paranoid as we must be sure to apply the fix */
-       if (pci_read_config_word(pdev, 0x40, &reg) != 0)
-               goto fail;
-       reg &= 0xDFFF;
-       if (pci_write_config_word(pdev, 0x40, reg) != 0)
-               goto fail;
-       printk(KERN_INFO DRV_NAME ": disabled chipset readahead.\n");
-
-       port_info[0] = &info;
-       port_info[1] = &info;
-       return ata_pci_init_one(pdev, port_info, 2);
-fail:
+       if (rz1000_fifo_disable(pdev) == 0) {
+               port_info[0] = &info;
+               port_info[1] = &info;
+               return ata_pci_init_one(pdev, port_info, 2);
+       }
        printk(KERN_ERR DRV_NAME ": failed to disable read-ahead on chipset..\n");
        /* Not safe to use so skip */
        return -ENODEV;
 }
 
+static int rz1000_reinit_one(struct pci_dev *pdev)
+{
+       /* If this fails on resume (which is a "cant happen" case), we
+          must stop as any progress risks data loss */
+       if (rz1000_fifo_disable(pdev))
+               panic("rz1000 fifo");
+       return ata_pci_device_resume(pdev);
+}
+
 static const struct pci_device_id pata_rz1000[] = {
        { PCI_VDEVICE(PCTECH, PCI_DEVICE_ID_PCTECH_RZ1000), },
        { PCI_VDEVICE(PCTECH, PCI_DEVICE_ID_PCTECH_RZ1001), },
@@ -182,7 +198,9 @@ static struct pci_driver rz1000_pci_driver = {
        .name           = DRV_NAME,
        .id_table       = pata_rz1000,
        .probe          = rz1000_init_one,
-       .remove         = ata_pci_remove_one
+       .remove         = ata_pci_remove_one,
+       .suspend        = ata_pci_device_suspend,
+       .resume         = rz1000_reinit_one,
 };
 
 static int __init rz1000_init(void)