Hi, all
This patch makes libata "Snoop SET FEATURES - WRITE CACHE ENABLE/DISABLE
command" and clean the things up(e.g. revalidate and rescan).
Here is the processing path:
1 in ata_scsi_qc_complete(), if we find that a "SET FEATURES - WRITE CACHE
ENABLE/DISABLE" command is executed successfully, we schedule the according
port to do revalidation
2 in ata_dev_revalidate(), if we find that the "write cahce enable bit" was
changed, set port flags in order to schedule scsi_rescan_device() later in
ata_scsi_error()
3 in ata_scsi_error(), if ATA_FLAG_SCSI_RESCAN is set for ap->flags, we
queue the ata_scsi_dev_rescan() to work_queue "ata_scsi_wq"
4 at last, scsi_rescan_device() is invoked, so the current state of "write
cahce enable bit" is propogated to SCSI layer.
The patch is against the curretn #upstream. Your comments are welcome.
Thanks,
Forrest
Signed-off-by: Zhao, Forrest <forrest.zhao@xxxxxxxxx>
---
drivers/scsi/libata-core.c | 17 +++++++++++++++++
drivers/scsi/libata-eh.c | 5 ++++-
drivers/scsi/libata-scsi.c | 35 ++++++++++++++++++++++++++++++++++-
drivers/scsi/libata.h | 2 ++
include/linux/ata.h | 3 +++
include/linux/libata.h | 4 +++-
6 files changed, 63 insertions(+), 3 deletions(-)
bc7324f8b2629241df4120743618d5454ea1834a
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 074a46e..889a15e 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -69,6 +69,8 @@ static void ata_dev_xfermask(struct ata_
static unsigned int ata_unique_id = 1;
static struct workqueue_struct *ata_wq;
+struct workqueue_struct *ata_scsi_wq;
+
int atapi_enabled = 1;
module_param(atapi_enabled, int, 0444);
MODULE_PARM_DESC(atapi_enabled, "Enable discovery of ATAPI devices (0=off, 1=on)");
@@ -2911,6 +2913,13 @@ int ata_dev_revalidate(struct ata_device
goto fail;
}
+ /* if the write cahce enable bit is changed, set port flags
+ * in order to schedule scsi_rescan_device() later in
+ * ata_scsi_error()
+ */
+ if ((dev->id[85] & (1 << 5)) != (id[85] & (1 << 5)))
+ dev->ap->flags |= ATA_FLAG_SCSI_RESCAN;
+
memcpy(dev->id, id, sizeof(id[0]) * ATA_ID_WORDS);
/* configure device according to the new ID */
@@ -5160,6 +5169,7 @@ static void ata_host_init(struct ata_por
ap->last_ctl = 0xFF;
INIT_WORK(&ap->port_task, NULL, NULL);
+ INIT_WORK(&ap->scsi_rescan_task, ata_scsi_dev_rescan, ap);
INIT_LIST_HEAD(&ap->eh_done_q);
/* set cable type */
@@ -5565,6 +5575,12 @@ static int __init ata_init(void)
if (!ata_wq)
return -ENOMEM;
+ ata_scsi_wq = create_singlethread_workqueue("ata_scsi");
+ if (!ata_scsi_wq) {
+ destroy_workqueue(ata_wq);
+ return -ENOMEM;
+ }
+
printk(KERN_DEBUG "libata version " DRV_VERSION " loaded.\n");
return 0;
}
@@ -5572,6 +5588,7 @@ static int __init ata_init(void)
static void __exit ata_exit(void)
{
destroy_workqueue(ata_wq);
+ destroy_workqueue(ata_scsi_wq);
}
module_init(ata_init);
diff --git a/drivers/scsi/libata-eh.c b/drivers/scsi/libata-eh.c
index 71b45ad..241aa49 100644
--- a/drivers/scsi/libata-eh.c
+++ b/drivers/scsi/libata-eh.c
@@ -286,9 +286,12 @@ void ata_scsi_error(struct Scsi_Host *ho
/* clean up */
spin_lock_irqsave(hs_lock, flags);
+ if (ap->flags & ATA_FLAG_SCSI_RESCAN)
+ queue_work(ata_scsi_wq, &ap->scsi_rescan_task);
+
if (ap->flags & ATA_FLAG_RECOVERED)
ata_port_printk(ap, KERN_INFO, "EH complete\n");
- ap->flags &= ~ATA_FLAG_RECOVERED;
+ ap->flags &= ~(ATA_FLAG_RECOVERED | ATA_FLAG_SCSI_RESCAN);
spin_unlock_irqrestore(hs_lock, flags);
diff --git a/drivers/scsi/libata-scsi.c b/drivers/scsi/libata-scsi.c
index 9e5cb9f..c49b9bd 100644
--- a/drivers/scsi/libata-scsi.c
+++ b/drivers/scsi/libata-scsi.c
@@ -1269,6 +1269,18 @@ static void ata_scsi_qc_complete(struct
u8 *cdb = cmd->cmnd;
int need_sense = (qc->err_mask != 0);
+ /* We snoop the SET_FEATURES - Write Cache ON/OFF command, and
+ * schedule EH_REVALIDATE operation to update the IDENTIFY DEVICE
+ * cache
+ */
+ if (((cdb[0] == ATA_16) || (cdb[0] == ATA_12)) &&
+ (!(cdb[2] & 0x20)) && (qc->tf.command == ATA_CMD_SET_FEATURES) &&
+ ((qc->tf.feature == SETFEATURES_WC_ON) ||
+ (qc->tf.feature == SETFEATURES_WC_OFF))) {
+ qc->ap->eh_info.action = ATA_EH_REVALIDATE;
+ ata_port_schedule_eh(qc->ap);
+ }
+
/* For ATA pass thru (SAT) commands, generate a sense block if
* user mandated it or if there's an error. Note that if we
* generate because the user forced us to, a check condition
@@ -2744,9 +2756,30 @@ void ata_scsi_scan_host(struct ata_port
return;
for (i = 0; i < ATA_MAX_DEVICES; i++) {
+ struct scsi_device *sdev;
+ dev = &ap->device[i];
+
+ if (!ata_dev_enabled(dev) || dev->sdev)
+ continue;
+ sdev = __scsi_add_device(ap->host, 0, i, 0, NULL);
+ if(!IS_ERR(sdev)){
+ dev->sdev = sdev;
+ scsi_device_put(sdev);
+ }
+ }
+}
+
+void ata_scsi_dev_rescan(void *data)
+{
+ struct ata_port *ap = data;
+ struct ata_device *dev;
+ unsigned int i;
+
+ for (i = 0; i < ATA_MAX_DEVICES; i++) {
dev = &ap->device[i];
if (ata_dev_enabled(dev))
- scsi_scan_target(&ap->host->shost_gendev, 0, i, 0, 0);
+ scsi_rescan_device(&(dev->sdev->sdev_gendev));
}
}
+
diff --git a/drivers/scsi/libata.h b/drivers/scsi/libata.h
index b76ad7d..352d332 100644
--- a/drivers/scsi/libata.h
+++ b/drivers/scsi/libata.h
@@ -39,6 +39,7 @@ struct ata_scsi_args {
};
/* libata-core.c */
+extern struct workqueue_struct *ata_scsi_wq;
extern int atapi_enabled;
extern int atapi_dmadir;
extern int libata_fua;
@@ -99,6 +100,7 @@ extern void ata_scsi_rbuf_fill(struct at
unsigned int (*actor) (struct ata_scsi_args *args,
u8 *rbuf, unsigned int buflen));
extern void ata_schedule_scsi_eh(struct Scsi_Host *shost);
+extern void ata_scsi_dev_rescan(void *data);
/* libata-eh.c */
extern enum scsi_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd);
diff --git a/include/linux/ata.h b/include/linux/ata.h
index c494e1c..3671af8 100644
--- a/include/linux/ata.h
+++ b/include/linux/ata.h
@@ -181,6 +181,9 @@ enum {
XFER_PIO_0 = 0x08,
XFER_PIO_SLOW = 0x00,
+ SETFEATURES_WC_ON = 0x02, /* Enable write cache */
+ SETFEATURES_WC_OFF = 0x82, /* Disable write cache */
+
/* ATAPI stuff */
ATAPI_PKT_DMA = (1 << 0),
ATAPI_DMADIR = (1 << 2), /* ATAPI data dir:
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 9c60b4a..687564d 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -159,6 +159,7 @@ enum {
ATA_FLAG_EH_PENDING = (1 << 16), /* EH pending */
ATA_FLAG_FROZEN = (1 << 17), /* port is frozen */
ATA_FLAG_RECOVERED = (1 << 18), /* recovery action performed */
+ ATA_FLAG_SCSI_RESCAN = (1 << 19), /* scsi device rescan is scheduled */
ATA_FLAG_DISABLED = (1 << 22), /* port is disabled, ignore it */
ATA_FLAG_SUSPENDED = (1 << 23), /* port is suspended (power) */
@@ -402,6 +403,7 @@ struct ata_device {
unsigned long flags; /* ATA_DFLAG_xxx */
unsigned int class; /* ATA_DEV_xxx */
unsigned int devno; /* 0 or 1 */
+ struct scsi_device *sdev; /* attached SCSI device */
u16 id[ATA_ID_WORDS]; /* IDENTIFY xxx DEVICE data */
u8 pio_mode;
u8 dma_mode;
@@ -484,7 +486,7 @@ struct ata_port {
struct ata_host_set *host_set;
struct device *dev;
- struct work_struct port_task;
+ struct work_struct port_task, scsi_rescan_task;
unsigned int hsm_task_state;
--
1.2.6
-
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