Re: [PATCH 0/2] usb: serial: handle -ENODEV and -EPROTO quietly

From: Jeremiah Mahler
Date: Mon Dec 15 2014 - 07:53:13 EST


On Mon, Dec 15, 2014 at 11:23:21AM +0100, Johan Hovold wrote:
> On Thu, Dec 11, 2014 at 03:29:52PM -0800, Jeremiah Mahler wrote:
> > If a USB serial device (e.g. /dev/ttyUSB0) with an active program is
> > unplugged, a bunch of -ENODEV and -EPROTO errors will be produced in the
> > logs. This patch set quiets these messages without changing the
> > original behavior.
> Don't unplug devices that are in use then. ;)
I knew someone was going to say that :-)

> > This change is beneficial when using daemons such as slcand, which is
> > similar to pppd or slip, that cannot determine whether they should exit
> > until after the USB serial device is unplugged. Producing these error
> > messages for a normal use case is not helpful.
> Your patches would hide these errors when they occur during normal use
> (e.g. EPROTO).
> Receiving an error message when unplugging an active device should not
> surprise anyone. And at least you know where it came from (and it's
> right there in the logs as well).
> Johan

Hmm. Yes, I can see why quieting -EPROTO would be bad because it would
hide protocol errors which we want to know about.

I need to re-think this patch.

Thanks for the review,
- Jeremiah Mahler
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