[PATCH 2/3] drm/display/dp: Define function to setup Extended wake time

Dmitry Baryshkov dmitry.baryshkov at linaro.org
Tue Jan 21 10:20:50 UTC 2025


On Tue, Jan 21, 2025 at 11:35:21AM +0530, Suraj Kandpal wrote:
> Extended wake timeout request helps to give additional
> time by reading the DPCD register through which sink requests the
> minimal amount of time required to wake the sink up.
> Source  device shall keep retying the AUX tansaction till the
> extended timeout that is being granted for LTTPRs from the
> sink device.
> 
> Spec: DP v2.1 Section 3.6.12.3
> Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
> ---
>  drivers/gpu/drm/display/drm_dp_helper.c | 47 +++++++++++++++++++++++++
>  include/drm/display/drm_dp_helper.h     |  1 +
>  2 files changed, 48 insertions(+)
> 
> diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c
> index da3c8521a7fa..9eae5ee85b13 100644
> --- a/drivers/gpu/drm/display/drm_dp_helper.c
> +++ b/drivers/gpu/drm/display/drm_dp_helper.c
> @@ -459,6 +459,53 @@ void drm_dp_lttpr_link_train_channel_eq_delay(const struct drm_dp_aux *aux,
>  }
>  EXPORT_SYMBOL(drm_dp_lttpr_link_train_channel_eq_delay);
>  

Please provide kernel doc for this function.

> +void drm_dp_lttpr_wake_timeout_setup(struct drm_dp_aux *aux, bool transparent_mode)
> +{
> +	u8 val = 1;
> +	int ret;
> +

-- 
With best wishes
Dmitry


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