lkml.org 
[lkml]   [2014]   [Nov]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] USB: cdc-acm: add quirk for control-line state requests
From
Date
On Fri, 2014-11-07 at 10:16 +0100, Johan Hovold wrote:
> On Fri, Nov 07, 2014 at 10:05:12AM +0100, Oliver Neukum wrote:
> > On Thu, 2014-11-06 at 18:08 +0100, Johan Hovold wrote:
> > > Add new quirk for devices that cannot handle control-line state
> > > requests.
> > >
> > > Note that we currently send these requests to all devices, regardless
> > > of
> > > whether they claim to support it, but that errors are only logged if
> > > support is claimed.
> >
> > That makes me wonder whether we should do this. What do you think?
>
> My interpretation was that it's done this way as there may be devices
> with broken CDC headers which fail to set the corresponding capability
> bits, but still support the request (c.f. our recent not-a-modem
> discussion).

Oh well, yes I don't like it, but we can't risk the change.

> In that case, always attempting the request, but only reporting errors
> if support was claimed, makes sense.
>
> As changing this behaviour now would risk breaking such devices, I
> think black-listing (i.e. this patch) is preferred moving forward.

Unfortunately, yes.

Regards
Oliver




\
 
 \ /
  Last update: 2014-11-07 12:01    [W:0.069 / U:0.344 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site