[U-Boot] [PATCH v2 3/3] test: ums: Add script for testing UMS gadget operation

[Stephen Warren <swarren@wwwdotorg.org>]

On 08/14/2014 06:41 AM, Lukasz Majewski wrote:
> This commit adds new test for UMS USB gadget to u-boot mainline tree.
> It is similar in operation to the one already available in test/dfu
> directory.

This looks good, although I have a few small comments...

> diff --git a/test/ums/README b/test/ums/README

> +Example usage:
> +1. On the target:
> +   create UMS exportable partitions (with e.g. gpt write)

I'd like to avoid that requirement. Perhaps the script can operate on 
raw devices without a partition table too. Can we enhance the script so 
that if the user specifies - as the partition ID, then $PART_NUM gets 
set to '' and hence the whole device is used?

If you do that, I'd like to add the following to the line I quoted above:

, or specify a partition ID of - to use the entire device.

You might want to insert an extra step in the documentation here:

Create a filesystem on the partition or device, or pass the -f option to 
the test script.

> diff --git a/test/ums/ums_gadget_test.sh b/test/ums/ums_gadget_test.sh

> +idVendor=`find /sys -type f -name "idVendor" -exec grep -w $VID {} \;`
> +idProduct=`find /sys -type f -name "idProduct" -exec grep -w $PID {} \;`
> +if [ -z "$idVendor" ] || [ -z "$idProduct" ]; then
> +    echo "Device $VID:$PID not connected!"
> +    exit 0
> +fi

That ensures that the given VID/PID exist somewhere, but not necessarily 
even on the same USB device.

> +USB_DEV=`find /sys -type f -name "idProduct" -exec grep -l $PID {} \;`
 > +USB_DEV=`dirname $USB_DEV`

... and that simply finds a USB device with a matching PID, but ignores 
the VID.

This might work better:

#!/bin/bash

VID=0955
PID=701a

for f in `find /sys -type f -name idProduct`; do
     d=`dirname ${f}`
     if [ `cat ${d}/idVendor` != "${VID}" ]; then
         continue
     fi
     if [ `cat ${d}/idProduct` != "${PID}" ]; then
         continue
     fi
     USB_DEV=${d}
     break
done

if [ -z "${USB_DEV}" ]; then
     echo "Connect target"
     echo "e.g. ums 0 mmc 0"
     exit 1
fi

echo ${USB_DEV}

 > +MEM_DEV=`find $USB_DEV -name "sd[a-z]" | awk -F/ '{print $(NF)}' -`

"-type d" might be a good idea there.

That's probably OK, although it worries me slightly to rely on the 
naming convention of the device. If the code above doesn't work for some 
people, perhaps we could find a file named "dev", and extract the device 
major/minor from it. However, we'd need some complex logic to 
distinguish between the many files named "dev"; in ${USB_DEV}/ itself, 
the various partitions on the device, and the scsi_generic and "bsg" 
(whatever that is) devices. So, it's probably not worth changing that now.