Commit 3057ac3c authored by zhao, forrest's avatar zhao, forrest Committed by Jeff Garzik
Browse files

[PATCH] Snoop SET FEATURES - WRITE CACHE ENABLE/DISABLE command(v5) 



This patch makes libata snoop 'SET FEATURES - WRITE CACHE
ENABLE/DISABLE' command, executing requisite revalidation processes
to update cached data.

Signed-off-by: default avatarForrest Zhao <forrest.zhao@intel.com>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent 39b07ce6

drivers/scsi/libata-core.c

+1 −0
Original line number Diff line number Diff line
@@ -5194,6 +5194,7 @@ static void ata_host_init(struct ata_port *ap, struct Scsi_Host *host, 


	INIT_WORK(&ap->port_task, NULL, NULL);

	INIT_WORK(&ap->hotplug_task, ata_scsi_hotplug, ap);

	INIT_WORK(&ap->scsi_rescan_task, ata_scsi_dev_rescan, ap);

	INIT_LIST_HEAD(&ap->eh_done_q);

	init_waitqueue_head(&ap->eh_wait_q);

drivers/scsi/libata-eh.c

+3 −0
Original line number Diff line number Diff line
@@ -1554,6 +1554,9 @@ static int ata_eh_revalidate_and_attach(struct ata_port *ap, 
			if (rc)

				break;



			/* schedule the scsi_rescan_device() here */

			queue_work(ata_aux_wq, &(ap->scsi_rescan_task));



			ehc->i.action &= ~ATA_EH_REVALIDATE;

		} else if (dev->class == ATA_DEV_UNKNOWN &&

			   ehc->tries[dev->devno] &&

drivers/scsi/libata-scsi.c

+36 −0
Original line number Diff line number Diff line
@@ -1306,6 +1306,17 @@ static void ata_scsi_qc_complete(struct ata_queued_cmd *qc) 
	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 (!need_sense && (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
@@ -2992,3 +3003,28 @@ static int ata_scsi_user_scan(struct Scsi_Host *shost, unsigned int channel, 


	return rc;

}



/**

 *      ata_scsi_dev_rescan - initiate scsi_rescan_device()

 *      @data: Pointer to ATA port to perform scsi_rescan_device()

 *

 *      After ATA pass thru (SAT) commands are executed successfully,

 *      libata need to propagate the changes to SCSI layer.

 *

 *      LOCKING:

 *      Kernel thread context (may sleep).

 */

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_rescan_device(&(dev->sdev->sdev_gendev));

	}

}

drivers/scsi/libata.h

+1 −0
Original line number Diff line number Diff line
@@ -104,6 +104,7 @@ extern void ata_scsi_rbuf_fill(struct ata_scsi_args *args, 
                        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);

include/linux/ata.h

+3 −0
Original line number Diff line number Diff line
@@ -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: