On Sat, 14 Apr 2012 00:24:03 +0100 Chris Wilson <chris at chris-wilson.co.uk> wrote: > On Fri, 13 Apr 2012 16:05:14 -0700, Ben Widawsky <ben at bwidawsk.net> > wrote: > > Dumb binary interfaces which allow root-only updates of our cache > > remapping registers. See intel-gpu-tools for how this can/should be > > used. > > Initial comments: don't bother posting a read just before a read, and > do return errors from the sysfs read/write functions (the return > value is signed for that purpose). A lesser issue is that if you are > worried about necessity of posting-reads, you should also worry about > the effect of the weak ordering of writes. > -Chris > Thanks for the advice on the sysfs return values. Some of the code I was referring from just returns 0, but this seems to be not the right thing to do after looking further into it. As for the POSTING_READ it was intentional. Unless reads are always in order??? I have to make sure the clock gating disable propogates before I can read the L3 registers. Ben
