On Mon, Aug 20, 2018 at 12:10:08PM -0700, Pandiyan, Dhinakaran wrote: > > > On Mon, 2018-08-20 at 10:15 +0300, Jani Nikula wrote: > > On Fri, 20 Jul 2018, Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> wrote: > > > Instead of using a backchannel if some dpcd read failed we > > > can show that directly on debugfs output. > > > > > > We are not returning an error because we might still want > > > to know if sub-sequent reads works, but we shouldn't > > > need to check 2 places to see why reg is not on the list. > > > > Should we just nuke this debugfs and use the aux chardev interface to > > dpcd instead? > > Given that this debugfs does not print decoded information, I think, it > offers very little benefit over direct reads. We also print some DPCD's > in dmesg, so I'm in favour of killing it. Don't see the file being used > in IGTs either. > > Your comment also reminds about the IGT tool that Tarun started writing > for reading DPCD. There might be people out there using this for debug. So we should first be able to do this in some place like IGT: https://patchwork.freedesktop.org/series/48470/ ? then we remove. But that discussion might take a while. So I'd like to move with this fix here now and remove dpcd_show completely when we create some infrastructure on IGT. > > -DK > > > > > > BR, > > Jani. > > > > > > > > Cc: Jani Nikula <jani.nikula@xxxxxxxxx> > > > Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@xxxxxxxxx> > > > Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> > > > --- > > > drivers/gpu/drm/i915/i915_debugfs.c | 4 ++-- > > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/gpu/drm/i915/i915_debugfs.c > > > b/drivers/gpu/drm/i915/i915_debugfs.c > > > index 59dc0610ea44..5d8da4e8c444 100644 > > > --- a/drivers/gpu/drm/i915/i915_debugfs.c > > > +++ b/drivers/gpu/drm/i915/i915_debugfs.c > > > @@ -4846,8 +4846,8 @@ static int i915_dpcd_show(struct seq_file *m, > > > void *data) > > > > > > err = drm_dp_dpcd_read(&intel_dp->aux, b->offset, > > > buf, size); > > > if (err <= 0) { > > > - DRM_ERROR("dpcd read (%zu bytes at %u) > > > failed (%zd)\n", > > > - size, b->offset, err); > > > + seq_printf(m, "dpcd read (%zu bytes at %u) > > > failed (%zd)\n", > > > + size, b->offset, err); > > > continue; > > > } > > > > _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
