[Intel-gfx] [PATCH 4/6] drm/i915: add FBC_IN_DBG_MASTER no_fbc_reason

[Chris Wilson]

On Wed, Jul 08, 2015 at 11:38:02AM +0200, Daniel Vetter wrote:
> On Tue, Jul 07, 2015 at 03:26:06PM -0300, Paulo Zanoni wrote:
> > From: Paulo Zanoni <paulo.r.zanoni at intel.com>
> > 
> > The poor in_dbg_master() check was the only one without a reason
> > string. Give it a reason string so it won't feel excluded.
> > 
> > Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
> > ---
> >  drivers/gpu/drm/i915/i915_drv.h  | 1 +
> >  drivers/gpu/drm/i915/intel_fbc.c | 6 +++++-
> >  2 files changed, 6 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> > index 4ef1764..52d07fb 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.h
> > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > @@ -935,6 +935,7 @@ struct i915_fbc {
> >  		FBC_MODULE_PARAM,
> >  		FBC_CHIP_DEFAULT, /* disabled by default on this chip */
> >  		FBC_ROTATION, /* rotation is not supported */
> > +		FBC_IN_DBG_MASTER, /* kernel debugger is active */
> 
> Oh dear this is dead code. kdbg uses the fbcon, which always uses
> untiled, which means fbc will never be enabled. Also we have 0 users and 0
> test coverage for kdbg on top of i915 (Jesse implemented it for fun years
> back). Imo just remove all this code.

A good kdbg integration would allow us to do allsorts of kprobes
debugging and igt fun. Ok, we could probably use kprobes...

* hatches evil plan to learn kprobes
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre