On Sat, 08 Oct 2016, Manasi Navare <manasi.d.navare@xxxxxxxxx> wrote: > This adds support in the kernel to handle link training compliance > requests and send a uevent to train at requested parameters. > In this patch series, if the link training fails in modeset, then a > hotplug uevent is added to a work queue and scheduled and failed link > parameters are stored in intel_dp structure. This uevent > gets executed after the modeset is completed and after locks are released. > In the modeset retry, modes are validated based on lower link rate from > the failed link rate value to prune the modes in intel_dp_mode_valid(). > The lower link rate is then used toc onfigure the pipe and link is retrained > at this lower link rate. > > I have tested this with DPR-120 and the compliance tests are passing. > The DP CTS spec is based on DP 1.2 spec and it only expects to reduce the link > rate and train at the max lane count without reducing the lane count. Lane count > reduction is added in DP 1.3 so Unigraf has agreed to add it to their next SW release. > Hence I have not implemented fallback for lane count. But I can add it if you think > we should add DP 1.3 link training algorithm. > > Please let me know your feedback on this. Compliance app is not required for link training > tests and so I have tested this fallback using kernel console mode on Source DUT. The question is, can you pass the link training tests using a userspace that responds to hotplug uevents? I think you mentioned a timeout in the CTS. If you're using fbdev, I think the retry modeset may happen faster than with a regular userspace. BR, Jani. > > v2: > * Corect the order of patches for correct dependencies > > Manasi Navare (4): > drm/i915; Add a function to return index of link rate > drm/i915: Add support for DP link training compliance > drm/i915: Work queue for uevent > drm/i915: Link Rate fallback on Link training failure > > Navare, Manasi D (1): > drm/i915: Change the placement of some static functions in intel_dp.c > > drivers/gpu/drm/i915/i915_drv.h | 2 + > drivers/gpu/drm/i915/intel_ddi.c | 10 +- > drivers/gpu/drm/i915/intel_dp.c | 277 ++++++++++++++++++-------- > drivers/gpu/drm/i915/intel_dp_link_training.c | 12 +- > drivers/gpu/drm/i915/intel_drv.h | 8 +- > 5 files changed, 217 insertions(+), 92 deletions(-) -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
