search for: drm_dp_lttpr_init

...et; This looks correct, but I had to go look at drm_dp_dpcd_writeb() to make sure it never returns 0 (for short transfers). > +} > +EXPORT_SYMBOL(drm_dp_lttpr_set_transparent_mode); This appears to be what the driver currently uses, but why not EXPORT_SYMBOL_GPL? > + > +/** > + * drm_dp_lttpr_init - init LTTPR transparency mode according to DP standard > + * > + * @aux: DisplayPort AUX channel > + * @lttpr_count: Number of LTTPRs > + * > + * Returns 0 on success or a negative error code on failure. > + */ > +int drm_dp_lttpr_init(struct drm_dp_aux *aux, int lttpr_count)...

...neric framework. > > Signed-off-by: Abel Vesa <abel.vesa at linaro.org> > --- > drivers/gpu/drm/display/drm_dp_helper.c | 50 +++++++++++++++++++++++++++++++++ > include/drm/display/drm_dp_helper.h | 2 ++ > 2 files changed, 52 insertions(+) > > +/** > + * drm_dp_lttpr_init - init LTTPR transparency mode according to DP standard > + * > + * @aux: DisplayPort AUX channel > + * @lttpr_count: Number of LTTPRs > + * > + * Returns 0 on success or a negative error code on failure. > + */ > +int drm_dp_lttpr_init(struct drm_dp_aux *aux, int lttpr_count)...

.... if (ret < 0) return ret; return (ret == 1) ? 0 : -EIO; > > > +} > > +EXPORT_SYMBOL(drm_dp_lttpr_set_transparent_mode); > > This appears to be what the driver currently uses, but why not > EXPORT_SYMBOL_GPL? > > > + > > +/** > > + * drm_dp_lttpr_init - init LTTPR transparency mode according to DP standard > > + * > > + * @aux: DisplayPort AUX channel > > + * @lttpr_count: Number of LTTPRs > > + * > > + * Returns 0 on success or a negative error code on failure. > > + */ > > +int drm_dp_lttpr_init(struct...

...t;abel.vesa at linaro.org> --- Changes in v3: - Picked-up T-b tag from Johan for the drm/dp transparent mode set helper patch - Re-worked the return value of the drm/dp transparet mode set helper - Added some more details about what the values of the lttpr_count arg is expected to be for the drm_dp_lttpr_init(), like Johan suggested. - Re-worked the non-transparent mode disable->enable so that the rollback doesn't happen unless enable failed. - Picked-up Lyude's R-b tag for the nouveau patch. - Dropped extra parantesis at the end of the drm_dp_lttpr_init() call in i915 patch. - Picked-up...

...> + > + 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 it's clear that you pass in the number of LTTPRs *or* an errno. > + > + drm_dp_lttpr_init(dp->aux, lttpr_count); > +} > + > static int msm_dp_display_process_hpd_high(struct msm_dp_display_private *dp) > { > struct drm_connector *connect...

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

...+{ + u8 val = enable ? DP_PHY_REPEATER_MODE_TRANSPARENT : + DP_PHY_REPEATER_MODE_NON_TRANSPARENT; + int ret = drm_dp_dpcd_writeb(aux, DP_PHY_REPEATER_MODE, val); + + if (ret < 0) + return ret; + + return (ret == 1) ? 0 : -EIO; +} +EXPORT_SYMBOL(drm_dp_lttpr_set_transparent_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...

...volunteer. BR, Jani. > > >> >> > +} >> > +EXPORT_SYMBOL(drm_dp_lttpr_set_transparent_mode); >> >> This appears to be what the driver currently uses, but why not >> EXPORT_SYMBOL_GPL? >> >> > + >> > +/** >> > + * drm_dp_lttpr_init - init LTTPR transparency mode according to DP standard >> > + * >> > + * @aux: DisplayPort AUX channel >> > + * @lttpr_count: Number of LTTPRs >> > + * >> > + * Returns 0 on success or a negative error code on failure. >> > + */ >> > +...

...ailing to switch to - * non-transparent mode fall-back to transparent link training mode, - * still taking into account any LTTPR common lane- rate/count limits. - */ - if (lttpr_count < 0) - goto out_reset_lttpr_count; - - if (!intel_dp_set_lttpr_transparent_mode(intel_dp, false)) { + ret = drm_dp_lttpr_init(&intel_dp->aux, lttpr_count); + if (ret) { lt_dbg(intel_dp, DP_PHY_DPRX, "Switching to LTTPR non-transparent LT mode failed, fall-back to transparent mode\n"); @@ -196,6 +180,8 @@ static int intel_dp_init_lttpr_phys(struct intel_dp *intel_dp, const u8 dpcd[DP_ got...

...int msm_dp_display_send_hpd_notification(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;...