linux-kernel - [PATCH v4 2/3] 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: <1339601291-3324-1-git-send-email-linkinjeon@gmail.com>
Date:	Wed, 13 Jun 2012 11:28:11 -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 <namjae.jeon@...sung.com>,
	Pankaj Kumar <pankaj.km@...sung.com>,
	Amit Sahrawat <a.sahrawat@...sung.com>
Subject: [PATCH v4 2/3] usb: storage: add support for write cache quirk on

From: Namjae Jeon <namjae.jeon@...sung.com>

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>
Acked-by: Alan Stern <stern@...land.harvard.edu>
---
 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/