search for: drm_dp_lttpr_count

...PM +0200, Abel Vesa wrote: > +static void msm_dp_display_lttpr_init(struct msm_dp_display_private *dp) > +{ > + int lttpr_count; > + > + if (drm_dp_read_lttpr_common_caps(dp->aux, dp->panel->dpcd, > + dp->lttpr_caps)) > + return; > + > + lttpr_count = drm_dp_lttpr_count(dp->lttpr_caps); I was gonna say shouldn't you handle errors here, but that explains the non-negative check I commented on the first patch in the series. This looks error prone, but I think you should at least update the kernel doc comment to drm_dp_lttpr_init() in the first patch so that...

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

...rent_mode); + +/** + * drm_dp_lttpr_init - init LTTPR transparency mode according to DP standard + * + * @aux: DisplayPort AUX channel + * @lttpr_count: Number of LTTPRs. Between 0 and 8, according to DP standard. + * Negative error code for any non-valid number. + * See drm_dp_lttpr_count(). + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_lttpr_init(struct drm_dp_aux *aux, int lttpr_count) +{ + int ret; + + if (!lttpr_count) + return 0; + + /* + * See DP Standard v2.0 3.6.6.1 about the explicit disabling of + * non-transparent mode and the disab...

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

On Wed, Dec 11, 2024 at 03:04:12PM +0200, Abel Vesa wrote: > According to the DisplayPort standard, LTTPRs have two operating > modes: > - non-transparent - it replies to DPCD LTTPR field specific AUX > requests, while passes through all other AUX requests > - transparent - it passes through all AUX requests. > > Switching between this two modes is done by the DPTX by

...otification(struct msm_dp_display_private *d return 0; } +static void msm_dp_display_lttpr_init(struct msm_dp_display_private *dp) +{ + int rc; + + if (drm_dp_read_lttpr_common_caps(dp->aux, dp->panel->dpcd, + dp->lttpr_caps)) + return; + + rc = drm_dp_lttpr_init(dp->aux, drm_dp_lttpr_count(dp->lttpr_caps)); + if (rc) + DRM_ERROR("failed to set LTTPRs transparency mode, rc=%d\n", rc); +} + static int msm_dp_display_process_hpd_high(struct msm_dp_display_private *dp) { struct drm_connector *connector = dp->msm_dp_display.connector; const struct drm_display_info *...