[PATCH] pata_rz1000: Force readahead off on resume

Alan
2006-11-22T17:28:25Z

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>

diff -u --new-file --recursive --exclude-from /usr/src/exclude linux.vanilla-2.6.19-rc5-mm2/drivers/ata/pata_rz1000.c linux-2.6.19-rc5-mm2/drivers/ata/pata_rz1000.c
--- linux.vanilla-2.6.19-rc5-mm2/drivers/ata/pata_rz1000.c 2006-11-15 13:26:00.000000000 +0000
+++ linux-2.6.19-rc5-mm2/drivers/ata/pata_rz1000.c 2006-11-22 14:46:07.904069272 +0000
@@ -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"

/**
@@ -91,6 +91,8 @@
.dma_boundary = ATA_DMA_BOUNDARY,
.slave_configure = ata_scsi_slave_config,
.bios_param = ata_std_bios_param,
+ .resume = ata_scsi_device_resume,
+ .suspend = ata_scsi_device_suspend,
};

static struct ata_port_operations rz1000_port_ops = {
@@ -128,6 +130,19 @@
.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
@@ -142,7 +157,6 @@
{
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,
@@ -153,23 +167,25 @@
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), },
@@ -181,7 +197,9 @@
.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)