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@xxxxxxxxxxx>
Signed-off-by: Pankaj Kumar<pankaj.km@xxxxxxxxxxx>
Signed-off-by: Amit Sahrawat<a.sahrawat@xxxxxxxxxxx>
---
drivers/scsi/sd.c | 9 +++++++--
include/scsi/scsi_device.h | 1 +
2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 6f0a4c6..33faf6d 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2259,8 +2259,13 @@ bad_sense:
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_quirk) {
+ sdkp->WCE = 1;
+ sd_printk(KERN_NOTICE, sdkp, "Assuming drive cache write back\n");
+ } else {
+ sd_printk(KERN_ERR, sdkp, "Assuming drive cache: write through\n");
+ sdkp->WCE = 0;
+ }
sdkp->RCD = 0;
sdkp->DPOFUA = 0;
}