Re: [RFC RESEND] serial: 8250: fix regression in 8250 uart driver

From: Andy Shevchenko
Date: Fri Sep 09 2016 - 10:28:44 EST


On Fri, 2016-09-09 at 08:57 -0500, Dinh Nguyen wrote:
>
> On 09/07/2016 12:16 PM, Andy Shevchenko wrote:
> >
> > On Tue, 2016-08-23 at 08:53 -0500, Dinh Nguyen wrote:
> > >
> > > Hi Andy,
> > >
> > > On 08/17/2016 06:14 AM, Andy Shevchenko wrote:
> > > >
> > > >
> > > >
> > > > I sent a v2 of the series for internal review, same you may
> > > > found on
> > > > [1]. If Heikki is okay to that I'll send it here.
> > > >
> > > > [1] https://bitbucket.org/andy-shev/linux/branch/topic%2Fdw%2Fqr
> > > > k
> > > >
> > >
> > > I tested this branch on SoCFPGA hardware and encountered this
> > > error[1].
> > > Doing a bisect led me to this commit[2].
> >
> > Forgot to add you to Cc list, there is new version there.
> >
>
> I'm no longer getting the previous error, but I am still seeing this:
>
> [ÂÂÂÂ6.025749] ttyS0 - failed to request DMA

As Peter told you your DMA engine doesn't provide everything UART driver
needs to establish such transfers.

My patchset does not prevent that check. It might be fixed, but I don't
know yet the proper way. Any suggestions you have, please, comment at
the series [1] directly.

[1]Âhttp://www.spinics.net/lists/linux-serial/msg23608.html

--
Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Intel Finland Oy