On Fri, Apr 12, 2019 at 12:05:29PM -0400, sunpeng.li@xxxxxxx wrote: > From: Leo Li <sunpeng.li@xxxxxxx> > > Hi all, > > This is a follup to this change made by Ville to add MST aux nodes: > https://github.com/vsyrjala/linux/commit/cac63f799ee2f5fbbe4f0a375383f13e03d640a5 > Patch 2/2 describes what I added on top. Cool. I take you got it to actually work? IIRC I never managed that :P > > Sending as an RFC since there are some items I'm not certain on: > > 1) Only expose aux devices for physical ports. FWICT, only DPTX and DPRX > can handle AUX transactions, leaving logical ports out. Hmm. My MST-foo is admittedly weak so I'm not sure. A quick trawl through the spec didn't provide any solid explanations either :( However eg. "Figure 2-83: Example Multi-function MST Branch-Sink Device Enumeration" in the DP 1.4 spec does appear to show kind of virtual DPCD thing behind a logical port. But I'm not really sure what than means. > 2) Naming of exposed AUX devices. I'm not sure if the scheme implemented > here is the best approach. I'm not sure magic naming schemes are the best. I believe we do have the sysfs hierarchy which allows you to find the right aux dev for the connector, but I do admit that can be a bit cumbersome to use. Also I'm not sure if all the things we might want to talk to are even represented by a connector, so maybe we do need something else. > > Let me know your thoughts, > Leo > > Leo Li (1): > drm/dp_mst: Use non-cyclic idr, add suffix option for aux device > > Ville Syrjälä (1): > drm/dp_mst: Register aux-dev nodes for MST ports > > drivers/gpu/drm/drm_crtc_helper_internal.h | 5 +- > drivers/gpu/drm/drm_dp_aux_dev.c | 21 ++++-- > drivers/gpu/drm/drm_dp_helper.c | 2 +- > drivers/gpu/drm/drm_dp_mst_topology.c | 109 +++++++++++++++++++++++++---- > include/drm/drm_dp_helper.h | 4 ++ > include/drm/drm_dp_mst_helper.h | 6 ++ > 6 files changed, 125 insertions(+), 22 deletions(-) > > -- > 2.7.4 -- Ville Syrjälä Intel _______________________________________________ amd-gfx mailing list amd-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/amd-gfx
