Re: [4.0-rc+] WARNING: CPU: 0 PID: 1 at ./drivers/dma/dmaengine.c:863 dma_async_device_register+0xe0/0x540()

[Maxime Ripard]

On Thu, Apr 09, 2015 at 06:31:13AM -0400, Peter Hurley wrote:
> On 04/09/2015 03:09 AM, Maxime Ripard wrote:
> > On Wed, Apr 08, 2015 at 12:07:14PM -0400, Peter Hurley wrote:
> >> On 04/08/2015 11:59 AM, Maxime Ripard wrote:
> >>> On Wed, Apr 08, 2015 at 11:53:33AM -0400, Peter Hurley wrote:
> >>>> On 03/05/2015 11:12 AM, Vinod Koul wrote:
> >>>>> On Thu, Mar 05, 2015 at 10:04:21AM -0500, Peter Hurley wrote:
> >>>>>>> First boot of 4.0-rc+ gave me [1] on a Beaglebone Black due to
> >>>>>>>
> >>>>> The warning is intentional to get driver fixed and give the right behaviour
> >>>>>
> >>>>> Felipe had sent a patch for this but that one needs an update
> >>>>
> >>>> Vinod,
> >>>>
> >>>> Felipe's patch never made it to mainline, and this warning is 
> >>>> still happening on 4.0-rc7 so please revert for 4.0-final.
> >>>
> >>> That patch isn't introducing any regression. I fail to see how that
> >>> justifies a revert so late in the release cycle.
> >>
> >> Arguably it never should have been introduced in the first place
> > 
> > Upon which arguments? So far, I've seen none but "my boot logs look
> > bad now".
> 
> 1. Every subsystem has drivers that don't fully conform to a desired
>    interface. If even a small fraction did this, everyone's logs would
>    be cluttered with this garbage. For that matter, if just the serial
>    subsystem alone did this, logs would be awash in warnings.

And a lot of subsystems do this for drivers where the way to fix this
is not clear and/or easy to obtain.

Which is exactly the case here.

> 2. Now _every_ dmaengine driver "fix" for this will need to be pushed
>    to -stable.

It won't. Such changes are not elligible, especially since they are
not critical fixes.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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