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authorAndrzej Pietrasiewicz <andrzej.p@samsung.com>2014-12-16 13:56:32 (GMT)
committerFelipe Balbi <balbi@ti.com>2015-01-12 18:13:25 (GMT)
commitcdbe287d271637cb90f239d6a826e2aed555c1d7 (patch)
tree0f8ee3bdb80e9121803da6973c92db018aa7bb17 /Documentation/usb
parentec91aff7630df1e1864d95f5efd25c212d484837 (diff)
Documentation: usb: MASS STORAGE function testing
Summary of how to test MASS STORAGE function of USB gadget. Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com> Signed-off-by: Felipe Balbi <balbi@ti.com>
Diffstat (limited to 'Documentation/usb')
-rw-r--r--Documentation/usb/gadget-testing.txt54
1 files changed, 54 insertions, 0 deletions
diff --git a/Documentation/usb/gadget-testing.txt b/Documentation/usb/gadget-testing.txt
index b13491d..01b9ffe 100644
--- a/Documentation/usb/gadget-testing.txt
+++ b/Documentation/usb/gadget-testing.txt
@@ -8,6 +8,7 @@ provided by gadgets.
5. FFS function
6. HID function
7. LOOPBACK function
+8. MASS STORAGE function
1. ACM function
@@ -228,3 +229,56 @@ device: run the gadget
host: test-usb
http://www.linux-usb.org/usbtest/testusb.c
+
+8. MASS STORAGE function
+========================
+
+The function is provided by usb_f_mass_storage.ko module.
+
+Function-specific configfs interface
+------------------------------------
+
+The function name to use when creating the function directory is "mass_storage".
+The MASS STORAGE function provides these attributes in its directory:
+files:
+
+ stall - Set to permit function to halt bulk endpoints.
+ Disabled on some USB devices known not to work
+ correctly. You should set it to true.
+ num_buffers - Number of pipeline buffers. Valid numbers
+ are 2..4. Available only if
+ CONFIG_USB_GADGET_DEBUG_FILES is set.
+
+and a default lun.0 directory corresponding to SCSI LUN #0.
+
+A new lun can be added with mkdir:
+
+$ mkdir functions/mass_storage.0/partition.5
+
+Lun numbering does not have to be continuous, except for lun #0 which is
+created by default. A maximum of 8 luns can be specified and they all must be
+named following the <name>.<number> scheme. The numbers can be 0..8.
+Probably a good convention is to name the luns "lun.<number>",
+although it is not mandatory.
+
+In each lun directory there are the following attribute files:
+
+ file - The path to the backing file for the LUN.
+ Required if LUN is not marked as removable.
+ ro - Flag specifying access to the LUN shall be
+ read-only. This is implied if CD-ROM emulation
+ is enabled as well as when it was impossible
+ to open "filename" in R/W mode.
+ removable - Flag specifying that LUN shall be indicated as
+ being removable.
+ cdrom - Flag specifying that LUN shall be reported as
+ being a CD-ROM.
+ nofua - Flag specifying that FUA flag
+ in SCSI WRITE(10,12)
+
+Testing the MASS STORAGE function
+---------------------------------
+
+device: connect the gadget, enable it
+host: dmesg, see the USB drives appear (if system configured to automatically
+mount)

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