Hello, i tried to interface to a usbtmc compatible scope (SIGLENT SDS1102CNL) and encountered a strange behavior while reading large data-chunks from the device using a 3.9.x-Kernel: Configuration and reading small amounts of data (*IDN) via usbtmc worked fine, i tried to read a channel like this: ---snip--- echo "C2:WF?" > /dev/usbtmc0 ; cat /dev/usbtmc0 > /tmp/test.raw ---snip--- The resulting file (see [1]) seemed to basically contain the expected waveform (Spikes at 0x2D0D and 0x3216) but additionally, starting at 0x7F3, there were several stings that clearly did not originate from the scope - in this case it looks like a part of a previously received E-Mail. dmesg showed this warning: [ 448.865620] usbtmc 4-5.3:1.0: Device returns more than requested: 620769889 > 4066 [ 453.895208] usbtmc 4-5.3:1.0: Unable to read data, error -110 The latest git-kernel (including Alexandre Peixotos rigol-patches) seems to have fixed leaking memory, it now aborts the whole request with "Device sent too small first packet". Florian [1] https://bugzilla.kernel.org/show_bug.cgi?id=60529 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
