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[3.11.y.z,extended,stable] Patch "usb-storage: enable multi-LUN scanning when needed" has been added to staging queue

Message ID 1392985462-4928-1-git-send-email-luis.henriques@canonical.com
State New
Headers show

Commit Message

Luis Henriques Feb. 21, 2014, 12:24 p.m. UTC
This is a note to let you know that I have just added a patch titled

    usb-storage: enable multi-LUN scanning when needed

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

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From 47cf798af88fcbb577a1ccc041a170b36976b10e Mon Sep 17 00:00:00 2001
From: Alan Stern <stern@rowland.harvard.edu>
Date: Thu, 30 Jan 2014 10:43:22 -0500
Subject: usb-storage: enable multi-LUN scanning when needed

commit 823d12c95c666fa7ab7dad208d735f6bc6afabdc upstream.

People sometimes create their own custom-configured kernels and forget
to enable CONFIG_SCSI_MULTI_LUN.  This causes problems when they plug
in a USB storage device (such as a card reader) with more than one
LUN.

Fortunately, we can tell fairly easily when a storage device claims to
have more than one LUN.  When that happens, this patch asks the SCSI
layer to probe all the LUNs automatically, regardless of the config
setting.

The patch also updates the Kconfig help text for usb-storage,
explaining that CONFIG_SCSI_MULTI_LUN may be necessary.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Thomas Raschbacher <lordvan@lordvan.com>
CC: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
CC: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 drivers/usb/storage/Kconfig    | 4 +++-
 drivers/usb/storage/scsiglue.c | 6 ++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

--
1.9.0
diff mbox

Patch

diff --git a/drivers/usb/storage/Kconfig b/drivers/usb/storage/Kconfig
index 8470e1b..1dd0604 100644
--- a/drivers/usb/storage/Kconfig
+++ b/drivers/usb/storage/Kconfig
@@ -18,7 +18,9 @@  config USB_STORAGE

 	  This option depends on 'SCSI' support being enabled, but you
 	  probably also need 'SCSI device support: SCSI disk support'
-	  (BLK_DEV_SD) for most USB storage devices.
+	  (BLK_DEV_SD) for most USB storage devices.  Some devices also
+	  will require 'Probe all LUNs on each SCSI device'
+	  (SCSI_MULTI_LUN).

 	  To compile this driver as a module, choose M here: the
 	  module will be called usb-storage.
diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c
index 5db1532..bb7bf19 100644
--- a/drivers/usb/storage/scsiglue.c
+++ b/drivers/usb/storage/scsiglue.c
@@ -78,6 +78,8 @@  static const char* host_info(struct Scsi_Host *host)

 static int slave_alloc (struct scsi_device *sdev)
 {
+	struct us_data *us = host_to_us(sdev->host);
+
 	/*
 	 * Set the INQUIRY transfer length to 36.  We don't use any of
 	 * the extra data and many devices choke if asked for more or
@@ -102,6 +104,10 @@  static int slave_alloc (struct scsi_device *sdev)
 	 */
 	blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1));

+	/* Tell the SCSI layer if we know there is more than one LUN */
+	if (us->protocol == USB_PR_BULK && us->max_lun > 0)
+		sdev->sdev_bflags |= BLIST_FORCELUN;
+
 	return 0;
 }