[Intel-gfx] [PATCH v2] drm/i915: Tune down init error message due to failure injection

[Imre Deak]

On ma, 2016-03-21 at 10:28 +0100, Daniel Vetter wrote:
> On Fri, Mar 18, 2016 at 11:15:35AM +0200, Imre Deak wrote:
> > On Fri, 2016-03-18 at 10:59 +0200, Joonas Lahtinen wrote:
> > > On pe, 2016-03-18 at 00:18 +0200, Imre Deak wrote:
> > > > On Thu, 2016-03-17 at 22:14 +0000, Chris Wilson wrote:
> > > > > 
> > > > > On Fri, Mar 18, 2016 at 12:09:30AM +0200, Imre Deak wrote:
> > > > > > 
> > > > > > On Thu, 2016-03-17 at 21:48 +0000, Chris Wilson wrote:
> > > > > > > 
> > > > > > > I would also like this to be the preferred
> > > > > > > DRM_ERROR reporting mechanism i.e. anytime we emit an
> > > > > > > ERROR
> > > > > > > we
> > > > > > > should
> > > > > > > be
> > > > > > > encouraging the user to file a bug, and do so in a user
> > > > > > > friendly
> > > > > > > fashion.
> > > > > > Ok, but only in i915 I assume. Should we also convert then
> > > > > > all
> > > > > > DRM_ERROR to dev_err - with an *ERROR* prefix - or still
> > > > > > use
> > > > > > DRM_ERROR?
> > > > > Within i915. I am thinking along the lines that no DRM_ERROR
> > > > > should
> > > > > exist that doesn't acknowlege that it is a user facing error
> > > > > message
> > > > > (i.e. written in plain English and is informative, and
> > > > > includes a
> > > > > bug
> > > > > reporting reference). So i915_report_error() or somesuch.
> > > > Ok, will give it a go.
> > > 
> > > Daniel didn't want i915 debugging/erroring mechanisms to deviate
> > > from
> > > core DRM. So I guess this would follow in the same category.
> > > 
> > > I'm all in for structuring a coherent debugging/error message
> > > logic
> > > and
> > > functions for it and then everyone can follow the suit.
> > 
> > The dev_err/dbg method has obvious advantages, like dynamic debug
> > or
> > showing the device instance, so I think that's something we want in
> > any
> > case. I don't see a problem with first rolling it out in i915 then
> > proposing it for more generic use.
> 
> Well that's just silly me trying to apply some pressure into making
> something that's compatible with DRM_*. Or well, porting those macros
> over
> to whatever the newfangled fancy thing is. Including keeping
> drm.debug
> alive with some hacks (we can write our own store functions, which
> could
> enable the right stuff with dynamic debugging, if we export a few
> funcs)
> so that the gazillion of howtos out there don't all break.

Yea, currently we'd output debug messages even in case of drm.debug==0.
I sent a patch that makes __i915_printk() behave the same as
DRM_DEBUG_DRIVER for debug messages. I think on top of that a more
fancy dynamic debug based filtering can be implemented later as you
suggest.

--Imre