lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Fri, 8 Aug 2014 03:10:34 +0800
From:	Wang YanQing <>
To:	Johan Hovold <>
Subject: Re: Resend Re: [PATCH v6] usb:serial:pl2303: add GPIOs interface on

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?

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

Powered by blists - more mailing lists