On Fri, Feb 03, 2012 at 11:10:09PM +0000, Chris Wilson wrote: > On Fri, 3 Feb 2012 14:31:41 -0800, Ben Widawsky <ben at bwidawsk.net> wrote: > > This is similar to a patch I wrote several months ago. It's been updated > > for the new FORCEWAKE_MT, and it also no longer clears the debug > > register as it may be helpful to get that for the error state. Also > > recommended by Chris Wilson, use WARN() instead of DRM_ERROR, so we can > > get a backtrace. > > > > Signed-off-by: Ben Widawsky <ben at bwidawsk.net> > > Can we use the read of GTFIFODBG in place of the POSTING_READ? And do we > really need to watch all the GTFIFODBG reads in the trace, or can I > squelch that noise with a I915_READ_NOTRACE? > -Chris TBH, I don't really understand POSTING_READ that well. If it just requires that any read request made it through to the MCH (or whatever), then sure I can replace the POSTING_READ. Obviously though this is reading GTFIFODBG, and not FORCEWAKE, so you tell me. As for READ_NOTRACE, I'm all for that. I'll wait to reroll the patch until you respond to the above though.