Add the usbtmc driver patch.

kernel/Makefile

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+
+obj-m += usbtmc.o
+
+all:
+	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
+
+clean:
+	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean
+

kernel/README

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+
+usbtmc driver patch
+===================
+
+It seems that Rigol oscilloscopes send big data (like screenshots) in an unusual way
+that corrupts the data at the receiving end. The driver has been patched to deal with
+this behaviour but only when the id of the device is found in a hardcoded list.
+
+"These patches implement a modification of the USBTMC protocol to allow operation with Rigol equipment.
+The usbtmc_read function is modified so if the quirk is active, the TMC header is sent with the size
+of the data as the whole size of the request. If the quirk is inactive, the TMC request is sent once
+per bulk transfer and with size limited to the bulk transfer size. In the case of the quirk, only the
+first response contains the TMC header and the others are just data."
+
+https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/log/drivers/usb/class/usbtmc.c
+
+Unfortunately, the latest line of oscilloscopes of Rigol (with product id 0x04b0) has not been
+added to the list into this driver.
+
+In order to do this, we have to make a small modification to the driver sourcecode and
+compile it.
+
+
+Compiling:
+----------
+
+Install: kernel-desktop-devel kernel-source
+
+In the following commands, replace the part "linux-3.16.7-21" with your actual kernel version.
+The easiest way to get this version is to use the command uname -r.
+
+cp /usr/src/linux-3.16.7-21/include/uapi/linux/usb/tmc.h .
+
+cp /usr/src/linux-3.16.7-21/drivers/usb/class/usbtmc.c .
+
+
+
+Somewhere around line 110 of the file usbtmc.c you will find the following code:
+
+static const struct usbtmc_ID_rigol_quirk usbtmc_id_quirk[] = {
+  { 0x1ab1, 0x0588 },
+  { 0, 0 }
+};
+
+
+Change it into:
+
+static const struct usbtmc_ID_rigol_quirk usbtmc_id_quirk[] = {
+  { 0x1ab1, 0x0588 },
+  { 0x1ab1, 0x04b0 },
+  { 0, 0 }
+};
+
+
+
+Now compile it:
+
+make
+
+
+Unload the old driver using the command:
+
+sudo rmmod usbtmc
+
+Load the new driver using the command:
+
+sudo insmod usbtmc.ko
+
+Now test the driver.
+
+When everything is ok, you can replace the old kernel module with the new one:
+
+sudo mv /lib/modules/3.16.7-21-desktop/kernel/drivers/usb/class/usbtmc.ko \
+/lib/modules/3.16.7-21-desktop/kernel/drivers/usb/class/usbtmc.ko.backup
+
+sudo cp ./usbtmc.ko /lib/modules/3.16.7-21-desktop/kernel/drivers/usb/class/
+
+
+
+The whole procedure must be repeated after a kernel update.
+