On Mon, Feb 03, 2025 at 12:57:55PM +0200, Abel Vesa wrote: > Looking at both i915 and nouveau DP drivers, both are setting the first > LTTPR (if found) in transparent mode first and then in non-transparent > mode, just like the DP v2.0 specification mentions in section 3.6.6.1. > > Being part of the standard, setting the LTTPR in a specific operation mode > can be easily moved in the generic framework. So do that by adding a new > helper. > > Then, the msm DP driver is lacking any kind of support for LTTPR handling, > so add it by reading the LTTPR caps for figuring out the number of LTTPRs > found on plug detect and then do exactly what the i915 and nouveau drivers > do with respect to toggling through operating modes, just like the > up-mentioned section from DP spec describes. > > At some point, link training per sub-segment will probably be needed, but > for now, toggling the operating modes seems to be enough at least for the > X Elite-based platforms that this patchset has been tested on. > > Signed-off-by: Abel Vesa <abel.vesa@xxxxxxxxxx> [...] > > --- > Abel Vesa (4): > drm/dp: Add helper to set LTTPRs in transparent mode > drm/nouveau/dp: Use the generic helper to control LTTPR transparent mode > drm/i915/dp: Use the generic helper to control LTTPR transparent mode Lyude, Jani, what would be your preferred way of merging these patches? Would you ack merging of those through drm-misc or would you prefer for the first patch only to be landed to drm-misc, which you can then pull into nouveau and i915 trees. > drm/msm/dp: Add support for LTTPR handling > > drivers/gpu/drm/display/drm_dp_helper.c | 61 ++++++++++++++++++++++ > .../gpu/drm/i915/display/intel_dp_link_training.c | 24 ++------- > drivers/gpu/drm/msm/dp/dp_display.c | 15 ++++++ > drivers/gpu/drm/nouveau/nouveau_dp.c | 17 +----- > include/drm/display/drm_dp_helper.h | 2 + > 5 files changed, 85 insertions(+), 34 deletions(-) > --- > base-commit: 00f3246adeeacbda0bd0b303604e46eb59c32e6e > change-id: 20241031-drm-dp-msm-add-lttpr-transparent-mode-set-136cd5bfde07 > > Best regards, > -- > Abel Vesa <abel.vesa@xxxxxxxxxx> > -- With best wishes Dmitry
