> -----Original Message----- > From: Intel-gfx [mailto:intel-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx] On Behalf Of > Chris Wilson > Sent: Saturday, May 23, 2015 5:11 PM > To: Mika Kuoppala > Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx; miku@xxxxxx > Subject: Re: [PATCH 2/2] drm/i915: Let hardware keep track of ctx > buf read pointer > > On Fri, May 22, 2015 at 08:17:22PM +0300, Mika Kuoppala wrote: > > We initialize the internal read pointer to zero on init/reset, > > but only the reset will actually zero the write pointer. > > This means that on module reload we might re-read context > > status buffers that were written prior reload. > > > > It is safest just to let the hardware keep track of the read pointer, > > so that we get valid value as there is no driver state involved. > > > > Signed-off-by: Mika Kuoppala <mika.kuoppala@xxxxxxxxx> > > --- > > drivers/gpu/drm/i915/i915_debugfs.c | 6 +++--- > > drivers/gpu/drm/i915/intel_lrc.c | 11 ++++------- > > drivers/gpu/drm/i915/intel_ringbuffer.h | 2 +- > > 3 files changed, 8 insertions(+), 11 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/i915_debugfs.c > b/drivers/gpu/drm/i915/i915_debugfs.c > > index fece922..b079dd3 100644 > > --- a/drivers/gpu/drm/i915/i915_debugfs.c > > +++ b/drivers/gpu/drm/i915/i915_debugfs.c > > @@ -2026,8 +2026,8 @@ static int i915_execlists(struct seq_file *m, void > *data) > > struct drm_i915_private *dev_priv = dev->dev_private; > > struct intel_engine_cs *ring; > > u32 status_pointer; > > - u8 read_pointer; > > - u8 write_pointer; > > + u32 read_pointer; > > + u32 write_pointer; > > I don't follow this change. It seems like this is to avoid having to > explicitly widen the type when converting the 32bit register value later > on? > > Otherwise I agree very much with the sentiment of the patch! > -Chris Do we still need to keep the sw pointer as a WA for this register field not being restored during power context restore on certain BDW GT3? Thomas. _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
