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[PATCH] ata_piix: fix ghost device probing by honoring PCS present bits

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Move out PCS handling from piix_sata_prereset() into
piix_sata_present_mask() and use it from newly implemented
piix_sata_softreset().  Class codes for devices which are indicated to
be absent by PCS are cleared to ATA_DEV_NONE.  This fixes ghost device
problem reported on ICH6 and 7.

This patch moves PCS handling from prereset to softreset, which makes
two behavior changes.

* perform softreset even when PCS indicates no device
* PCS handling is repeated before retrying softresets due to reset
  failures.

Both behavior changes are intended and more consistent with how other
drivers behave.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This commit is contained in:
Tejun Heo 2006-08-20 17:56:38 +09:00 committed by Jeff Garzik
parent d14b50cc60
commit f1a58ecae5
1 changed files with 43 additions and 17 deletions
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60
drivers/scsi/ata_piix.c
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@ -531,27 +531,25 @@ static void piix_pata_error_handler(struct ata_port *ap)
}
/**
* piix_sata_prereset - prereset for SATA host controller
* piix_sata_present_mask - determine present mask for SATA host controller
* @ap: Target port
*
* Reads and configures SATA PCI device's PCI config register
* Port Configuration and Status (PCS) to determine port and
* device availability. Return -ENODEV to skip reset if no
* device is present.
* Reads SATA PCI device's PCI config register Port Configuration
* and Status (PCS) to determine port and device availability.
*
* LOCKING:
* None (inherited from caller).
*
* RETURNS:
* 0 if device is present, -ENODEV otherwise.
* determined present_mask
*/
static int piix_sata_prereset(struct ata_port *ap)
static unsigned int piix_sata_present_mask(struct ata_port *ap)
{
struct pci_dev *pdev = to_pci_dev(ap->host_set->dev);
struct piix_host_priv *hpriv = ap->host_set->private_data;
const unsigned int *map = hpriv->map;
int base = 2 * ap->hard_port_no;
unsigned int present = 0;
unsigned int present_mask = 0;
int port, i;
u16 pcs;
@ -564,24 +562,52 @@ static int piix_sata_prereset(struct ata_port *ap)
continue;
if ((ap->flags & PIIX_FLAG_IGNORE_PCS) ||
(pcs & 1 << (hpriv->map_db->present_shift + port)))
present = 1;
present_mask |= 1 << i;
}
DPRINTK("ata%u: LEAVE, pcs=0x%x present=0x%x\n",
ap->id, pcs, present);
DPRINTK("ata%u: LEAVE, pcs=0x%x present_mask=0x%x\n",
ap->id, pcs, present_mask);
if (!present) {
ata_port_printk(ap, KERN_INFO, "SATA port has no device.\n");
ap->eh_context.i.action &= ~ATA_EH_RESET_MASK;
return 0;
return present_mask;
}
/**
* piix_sata_softreset - reset SATA host port via ATA SRST
* @ap: port to reset
* @classes: resulting classes of attached devices
*
* Reset SATA host port via ATA SRST. On controllers with
* reliable PCS present bits, the bits are used to determine
* device presence.
*
* LOCKING:
* Kernel thread context (may sleep)
*
* RETURNS:
* 0 on success, -errno otherwise.
*/
static int piix_sata_softreset(struct ata_port *ap, unsigned int *classes)
{
unsigned int present_mask;
int i, rc;
present_mask = piix_sata_present_mask(ap);
rc = ata_std_softreset(ap, classes);
if (rc)
return rc;
for (i = 0; i < ATA_MAX_DEVICES; i++) {
if (!(present_mask & (1 << i)))
classes[i] = ATA_DEV_NONE;
}
return ata_std_prereset(ap);
return 0;
}
static void piix_sata_error_handler(struct ata_port *ap)
{
ata_bmdma_drive_eh(ap, piix_sata_prereset, ata_std_softreset, NULL,
ata_bmdma_drive_eh(ap, ata_std_prereset, piix_sata_softreset, NULL,
ata_std_postreset);
}