This is a note to let you know that I've just added the patch titled
usb-storage: enable multi-LUN scanning when needed
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From 823d12c95c666fa7ab7dad208d735f6bc6afabdc Mon Sep 17 00:00:00 2001
From: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Date: Thu, 30 Jan 2014 10:43:22 -0500
Subject: usb-storage: enable multi-LUN scanning when needed
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@xxxxxxxxxxxxxxxxxxx>
Reported-by: Thomas Raschbacher <lordvan@xxxxxxxxxxx>
CC: Matthew Dharm <mdharm-usb@xxxxxxxxxxxxxxxxxx>
CC: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/storage/Kconfig | 4 +++-
drivers/usb/storage/scsiglue.c | 6 ++++++
2 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/storage/Kconfig b/drivers/usb/storage/Kconfig
index 8470e1b114f2..1dd0604d1911 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 18509e6c21ab..9d38ddc8da49 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;
}
--
1.8.5.1.163.gd7aced9
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