From: Alexander Kappner <agk@godking.net>
Date: Sat, 19 May 2018 04:50:15 +0000 (-0700)
Subject: usb-storage: Add support for FL_ALWAYS_SYNC flag in the UAS driver
X-Git-Tag: v4.18-rc1~136^2~46
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=8c4e97ddfe73a0958bb0abf7e6a3bc4cc3e04936;p=linux.git

usb-storage: Add support for FL_ALWAYS_SYNC flag in the UAS driver

The ALWAYS_SYNC flag is currently honored by the usb-storage driver but not UAS
and is required to work around devices that become unstable upon being
queried for cache. This code is taken straight from:
drivers/usb/storage/scsiglue.c:284

Signed-off-by: Alexander Kappner <agk@godking.net>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@vger.kernel.org>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c
index 6034c39b67d1..9e9de5452860 100644
--- a/drivers/usb/storage/uas.c
+++ b/drivers/usb/storage/uas.c
@@ -836,6 +836,12 @@ static int uas_slave_configure(struct scsi_device *sdev)
 	if (devinfo->flags & US_FL_BROKEN_FUA)
 		sdev->broken_fua = 1;
 
+	/* UAS also needs to support FL_ALWAYS_SYNC */
+	if (devinfo->flags & US_FL_ALWAYS_SYNC) {
+		sdev->skip_ms_page_3f = 1;
+		sdev->skip_ms_page_8 = 1;
+		sdev->wce_default_on = 1;
+	}
 	scsi_change_queue_depth(sdev, devinfo->qdepth - 2);
 	return 0;
 }