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pata_sl82c105: dual channel support

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Use qc_defer to serialize the two channels

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This commit is contained in:
Alan Cox 2008-01-28 16:08:23 +00:00 committed by Jeff Garzik
parent 4a537a5518
commit 92ba5d02d9
1 changed files with 31 additions and 2 deletions
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33
drivers/ata/pata_sl82c105.c
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@ -26,7 +26,7 @@
#include <linux/libata.h> #include <linux/libata.h>
#define DRV_NAME "pata_sl82c105" #define DRV_NAME "pata_sl82c105"
#define DRV_VERSION "0.3.2" #define DRV_VERSION "0.3.3"
enum { enum {
/* /*
@ -206,6 +206,34 @@ static void sl82c105_bmdma_stop(struct ata_queued_cmd *qc)
sl82c105_set_piomode(ap, qc->dev); sl82c105_set_piomode(ap, qc->dev);
} }
/**
* sl82c105_qc_defer - implement serialization
* @qc: command
*
* We must issue one command per host not per channel because
* of the reset bug.
*
* Q: is the scsi host lock sufficient ?
*/
static int sl82c105_qc_defer(struct ata_queued_cmd *qc)
{
struct ata_host *host = qc->ap->host;
struct ata_port *alt = host->ports[1 ^ qc->ap->port_no];
int rc;
/* First apply the usual rules */
rc = ata_std_qc_defer(qc);
if (rc != 0)
return rc;
/* Now apply serialization rules. Only allow a command if the
other channel state machine is idle */
if (alt && alt->qc_active)
return ATA_DEFER_PORT;
return 0;
}
static struct scsi_host_template sl82c105_sht = { static struct scsi_host_template sl82c105_sht = {
.module = THIS_MODULE, .module = THIS_MODULE,
.name = DRV_NAME, .name = DRV_NAME,
@ -245,6 +273,7 @@ static struct ata_port_operations sl82c105_port_ops = {
.bmdma_stop = sl82c105_bmdma_stop, .bmdma_stop = sl82c105_bmdma_stop,
.bmdma_status = ata_bmdma_status, .bmdma_status = ata_bmdma_status,
.qc_defer = sl82c105_qc_defer,
.qc_prep = ata_qc_prep, .qc_prep = ata_qc_prep,
.qc_issue = ata_qc_issue_prot, .qc_issue = ata_qc_issue_prot,
@ -312,7 +341,7 @@ static int sl82c105_init_one(struct pci_dev *dev, const struct pci_device_id *id
}; };
/* for now use only the first port */ /* for now use only the first port */
const struct ata_port_info *ppi[] = { &info_early, const struct ata_port_info *ppi[] = { &info_early,
&ata_dummy_port_info }; NULL };
u32 val; u32 val;
int rev; int rev;