Quoting Chris Wilson (2017-10-27 13:59:17) > Quoting Ville Syrjälä (2017-10-27 13:54:49) > > On Fri, Oct 27, 2017 at 01:45:35PM +0100, Chris Wilson wrote: > > > A purely recursive batch has the downside that it is a severe drain on > > > system resources (see commit f978cc027cd0 "lib/dummyload: Pad with a few > > > nops so that we do not completely hog the system") which can result in > > > the test being starved and failing to make reasonably progress. For more > > > reliable resets, also include an arbitration point. This should lessen > > > the efficacy of the hang... > > > > > > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > > > Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > > Cc: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx> > > > --- > > > lib/igt_gt.c | 10 +++++----- > > > 1 file changed, 5 insertions(+), 5 deletions(-) > > > > > > diff --git a/lib/igt_gt.c b/lib/igt_gt.c > > > index 89727d22..2aebad14 100644 > > > --- a/lib/igt_gt.c > > > +++ b/lib/igt_gt.c > > > @@ -313,12 +313,12 @@ igt_hang_t igt_hang_ctx(int fd, > > > len = 2; > > > if (intel_gen(intel_get_drm_devid(fd)) >= 8) > > > len++; > > > - b[0] = MI_BATCH_BUFFER_START | (len - 2); > > > - b[len] = MI_BATCH_BUFFER_END; > > > - b[len+1] = MI_NOOP; > > > - gem_write(fd, exec.handle, 0, b, sizeof(b)); > > > + b[0] = 0x5 << 24; /* ARB_CHk */ > > > > That seems to be gen4+ only. Also > > "This instruction can be placed only in a ring buffer, never in a batch > > buffer." > > Idea of since/until when? It's definitely listed for batches on gen8+. > > The good news being an unrecognised MI cmd it is skipped. Better news if > it causes a GPU hang ;) But it certainly doesn't work as an arbitration point on gen6, presuming that was what we were missing for the reset to function. -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
