AcoSail/kernel_optimize_test
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[SCSI] set to WCE if usb cache quirk is present.

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Make use of USB quirk method to identify such HDD while reading
the cache status in sd_probe(). If cache quirk is present for
the HDD, lets assume that cache is enabled and make WCE bit
equal to 1.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Pankaj Kumar <pankaj.km@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
This commit is contained in:
Namjae Jeon 2012-07-07 23:05:08 -04:00 committed by James Bottomley
parent 365a715009
commit b81478d82e
2 changed files with 8 additions and 2 deletions
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9
drivers/scsi/sd.c
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@ -2261,8 +2261,13 @@ sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
sd_printk(KERN_ERR, sdkp, "Asking for cache data failed\n");
defaults:
sd_printk(KERN_ERR, sdkp, "Assuming drive cache: write through\n");
sdkp->WCE = 0;
if (sdp->wce_default_on) {
sd_printk(KERN_NOTICE, sdkp, "Assuming drive cache: write back\n");
sdkp->WCE = 1;
} else {
sd_printk(KERN_ERR, sdkp, "Assuming drive cache: write through\n");
sdkp->WCE = 0;
}
sdkp->RCD = 0;
sdkp->DPOFUA = 0;
}

1
include/scsi/scsi_device.h
View File

@ -154,6 +154,7 @@ struct scsi_device {
unsigned no_read_capacity_16:1; /* Avoid READ_CAPACITY_16 cmds */
unsigned try_rc_10_first:1; /* Try READ_CAPACACITY_10 first */
unsigned is_visible:1; /* is the device visible in sysfs */
unsigned wce_default_on:1; /* Cache is ON by default */
DECLARE_BITMAP(supported_events, SDEV_EVT_MAXBITS); /* supported events */
struct list_head event_list; /* asserted events */