On Thu, Feb 05, 2015 at 04:11:00PM -0800, Jesse Barnes wrote: > On Wed, 14 Jan 2015 11:20:55 +0000 > Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote: > > > diff --git a/drivers/char/agp/intel-gtt.c > > b/drivers/char/agp/intel-gtt.c index 92aa43fa8d70..15685ca39193 100644 > > --- a/drivers/char/agp/intel-gtt.c > > +++ b/drivers/char/agp/intel-gtt.c > > @@ -225,7 +225,7 @@ static int i810_insert_dcache_entries(struct > > agp_memory *mem, off_t pg_start, > > intel_private.driver->write_entry(addr, i, type); > > } > > - readl(intel_private.gtt+i-1); > > + readl(intel_private.gtt+pg_start); > > Any idea why? This one scares me... is it that the read is being > serviced from the WC buffer w/o being flushed? Or is the compiler > optimizing the last read based on the previous write? The former. I checked the assembly to verify that the compiler wasn't playing tricks. -Chrier -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
