linux-kernel - [PATCH v4 2/2] usb: storage: add support for write cache quirk on

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-Id: <1339421331-2935-1-git-send-email-linkinjeon@gmail.com>
Date:	Mon, 11 Jun 2012 09:28:51 -0400
From:	Namjae Jeon <linkinjeon@...il.com>
To:	James.Bottomley@...senPartnership.com, gregkh@...uxfoundation.org,
	mdharm-usb@...-eyed-alien.net, stern@...land.harvard.edu,
	sshtylyov@...sta.com, bvanassche@....org
Cc:	linux-usb@...r.kernel.org, linux-scsi@...r.kernel.org,
	linux-kernel@...r.kernel.org, Namjae Jeon <linkinjeon@...il.com>,
	Namjae Jeon <namjae.jeon@...sung.com>,
	Pankaj Kumar <pankaj.km@...sung.com>,
	Amit Sahrawat <a.sahrawat@...sung.com>
Subject: [PATCH v4 2/2] usb: storage: add support for write cache quirk on

Add support for write cache quirk on usb hdd. scsi driver will be set to wce by detecting write cache quirk in quirk list when plugging usb hdd.

Signed-off-by: Namjae Jeon <namjae.jeon@...sung.com>
Signed-off-by: Pankaj Kumar <pankaj.km@...sung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@...sung.com>
---
 Documentation/kernel-parameters.txt |    2 ++
 drivers/usb/storage/scsiglue.c      |    5 +++++
 drivers/usb/storage/usb.c           |    5 ++++-
 include/linux/usb_usual.h           |    4 +++-
 4 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 86bdca9..2f88c9c 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2939,6 +2939,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 					initial READ(10) command);
 				o = CAPACITY_OK (accept the capacity
 					reported by the device);
+				p = WRITE_CACHE (the device cache is ON
+					by default);
 				r = IGNORE_RESIDUE (the device reports
 					bogus residue values);
 				s = SINGLE_LUN (the device has only one
diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c
index a324a5d..fe42547 100644
--- a/drivers/usb/storage/scsiglue.c
+++ b/drivers/usb/storage/scsiglue.c
@@ -230,6 +230,11 @@ static int slave_configure(struct scsi_device *sdev)
 					US_FL_SCM_MULT_TARG)) &&
 				us->protocol == USB_PR_BULK)
 			us->use_last_sector_hacks = 1;
+
+		/* Check if write cache default on flag is set or not */
+		if (us->fflags & US_FL_WRITE_CACHE)
+			sdev->wce_default_on = 1;
+
 	} else {
 
 		/* Non-disk-type devices don't need to blacklist any pages
diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c
index e23c30a..d012fe4 100644
--- a/drivers/usb/storage/usb.c
+++ b/drivers/usb/storage/usb.c
@@ -473,7 +473,7 @@ static void adjust_quirks(struct us_data *us)
 			US_FL_CAPACITY_OK | US_FL_IGNORE_RESIDUE |
 			US_FL_SINGLE_LUN | US_FL_NO_WP_DETECT |
 			US_FL_NO_READ_DISC_INFO | US_FL_NO_READ_CAPACITY_16 |
-			US_FL_INITIAL_READ10);
+			US_FL_INITIAL_READ10 | US_FL_WRITE_CACHE);
 
 	p = quirks;
 	while (*p) {
@@ -529,6 +529,9 @@ static void adjust_quirks(struct us_data *us)
 		case 'o':
 			f |= US_FL_CAPACITY_OK;
 			break;
+		case 'p':
+			f |= US_FL_WRITE_CACHE;
+			break;
 		case 'r':
 			f |= US_FL_IGNORE_RESIDUE;
 			break;
diff --git a/include/linux/usb_usual.h b/include/linux/usb_usual.h
index 17df360..e84e769 100644
--- a/include/linux/usb_usual.h
+++ b/include/linux/usb_usual.h
@@ -64,7 +64,9 @@
 	US_FLAG(NO_READ_CAPACITY_16,	0x00080000)		\
 		/* cannot handle READ_CAPACITY_16 */		\
 	US_FLAG(INITIAL_READ10,	0x00100000)			\
-		/* Initial READ(10) (and others) must be retried */
+		/* Initial READ(10) (and others) must be retried */	\
+	US_FLAG(WRITE_CACHE,	0x00200000)			\
+		/* Write Cache status is not available */
 
 #define US_FLAG(name, value)	US_FL_##name = value ,
 enum { US_DO_ALL_FLAGS };
-- 
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/