[Intel-gfx] [PATCH 0/5] Handle Link Training Failure during modeset

[Harry Wentland]

Overall this patch set makes sense but I think it would be good to move 
some stuff to common code instead of leaving it in i915. I'm thinking 
about patch 2 (setting the link status property) in particular but also 
tend to agree with Ville and Daniel about their comments for patch 5.

That said, should another driver need it it shouldn't be hard to pull 
that out.

Patch 1: Reviewed-by: Harry Wentland <harry.wentland at amd.com>

Patch 2-5: Acked-by: Harry Wentland <harry.wentland at amd.com>

Harry


On 2016-11-09 11:42 PM, Manasi Navare wrote:
> Link training failure is handled by lowering the link rate first
> until it reaches the minimum and keeping the lane count maximum
> and then lowering the lane count until it reaches minimim. These
> fallback values are saved and hotplug uevent is sent to the userspace
> after setting the connector link status property to BAD. Userspace
> should triiger another modeset on a uevent and if link status property
> is BAD. This will retrain the link at fallback values.
> This is repeated until the link is successfully trained.
>
> This has been validated to pass DP compliance.
>
> Manasi Navare (5):
>    drm: Add a new connector property for link status
>    drm/i915: Set link status property for DP connector
>    drm/i915: Update CRTC state if connector link status property changed
>    drm/i915: Find fallback link rate/lane count
>    drm/i915: Implement Link Rate fallback on Link training failure
>
>   drivers/gpu/drm/drm_atomic_helper.c           |   7 ++
>   drivers/gpu/drm/drm_connector.c               |  17 ++++
>   drivers/gpu/drm/i915/intel_ddi.c              |  21 +++-
>   drivers/gpu/drm/i915/intel_dp.c               | 138 +++++++++++++++++++++++++-
>   drivers/gpu/drm/i915/intel_dp_link_training.c |  12 ++-
>   drivers/gpu/drm/i915/intel_drv.h              |  12 ++-
>   include/drm/drm_connector.h                   |   7 +-
>   include/drm/drm_crtc.h                        |   5 +
>   include/uapi/drm/drm_mode.h                   |   4 +
>   9 files changed, 214 insertions(+), 9 deletions(-)
>