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authorAlan Stern <stern@rowland.harvard.edu>2014-01-30 10:43:22 -0500
committerBen Hutchings <ben@decadent.org.uk>2014-04-02 00:58:48 +0100
commitfecfa5d27e1a8f833d2d4d4705946c7aaa6b4e07 (patch)
tree5dd81c3297bf6413c2839f9bbca674f6ec530a1f
parentef5bc9a475f12442ace9b7cc9f22d2a7fc928fdc (diff)
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> [bwh: Backported to 3.2: - Adjust context - slave_alloc() already has a us_data pointer] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
-rw-r--r--drivers/usb/storage/Kconfig4
-rw-r--r--drivers/usb/storage/scsiglue.c4
2 files changed, 7 insertions, 1 deletions
diff --git a/drivers/usb/storage/Kconfig b/drivers/usb/storage/Kconfig
index 303c34b4973..3460ee83039 100644
--- a/drivers/usb/storage/Kconfig
+++ b/drivers/usb/storage/Kconfig
@@ -19,7 +19,9 @@ 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 13b8bcdf3db..eb660bb9dec 100644
--- a/drivers/usb/storage/scsiglue.c
+++ b/drivers/usb/storage/scsiglue.c
@@ -116,6 +116,10 @@ static int slave_alloc (struct scsi_device *sdev)
if (us->subclass == USB_SC_UFI)
sdev->sdev_target->pdt_1f_for_no_lun = 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;
}