On Tue, Aug 05, 2014 at 03:54:08PM +0200, Johan Hovold wrote: > > > I noticed that setting direction to output and setting the gpio high has > > > no effect on the read-back value (i.e. I still read back 0) for my > > > pl2303hx (note that my device has no easily accessible gpios so I > > > haven't verified the actual state of the output pin). > > > > > > What happens on your system? Is the read-back value still 0, even when > > > the GPIO output is actually high? Should we return the cached value in > > > this case? > > > > If i set direction to output, then I could control gpio high and low > > by set 1 or 0, and the read-back value is 1 or 0 according to high and > > low(I test high and low by oscillscope) > > > > I test it with my pl2303hx with only two gpios. > > > > Could you use usbmon to see whether the traffic is right according > > to comment in struct pl2303_gpio? > > The traffic appears correct judging from the debug output (which I > trust). Output-enable is reflected in register 0x81, but the value > isn't. > > What is the lsusb -v output for your device? Bus 001 Device 005: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port. It is strange your device doesn't work, I verify the control method by analyze usbmon output from linux host which has VirtualBox running gpio test program, but I don't have right to distribute the gpio test program I think, so I can't help you to figure out why it doesn't work for your device. > I suggest you just set the label to pl2303 until we have a valid > use-case that requires something more elaborate. Ok, but pl2303-gpio maybe a better name? Thanks. -- 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
