| Message ID | 20250103-drm-dp-msm-add-lttpr-transparent-mode-set-v3-3-5c367f4b0763@linaro.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | drm/dp: Rework LTTPR transparent mode handling and add support to msm driver | expand |
On Fri, Jan 03, 2025 at 02:58:17PM +0200, Abel Vesa wrote: > LTTPRs operating modes are defined by the DisplayPort standard and the > generic framework now provides a helper to switch between them, which > is handling the explicit disabling of non-transparent mode and its > disable->enable sequence mentioned in the DP Standard v2.0 section > 3.6.6.1. > > So use the new drm generic helper instead as it makes the code a bit > cleaner. > > Acked-by: Imre Deak <imre.deak@intel.com> > Signed-off-by: Abel Vesa <abel.vesa@linaro.org> > --- > .../gpu/drm/i915/display/intel_dp_link_training.c | 24 +++++----------------- > 1 file changed, 5 insertions(+), 19 deletions(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.c b/drivers/gpu/drm/i915/display/intel_dp_link_training.c > index 8b1977cfec503c70f07af716ee2c00e7605c6adf..c5bad311edf7b9a5cebb633b9e9692bae397f9ed 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c > +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c > @@ -119,9 +119,6 @@ intel_dp_set_lttpr_transparent_mode(struct intel_dp *intel_dp, bool enable) > u8 val = enable ? DP_PHY_REPEATER_MODE_TRANSPARENT : > DP_PHY_REPEATER_MODE_NON_TRANSPARENT; > > - if (drm_dp_dpcd_write(&intel_dp->aux, DP_PHY_REPEATER_MODE, &val, 1) != 1) > - return false; > - > intel_dp->lttpr_common_caps[DP_PHY_REPEATER_MODE - > DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV] = val; > > @@ -146,6 +143,7 @@ static bool intel_dp_lttpr_transparent_mode_enabled(struct intel_dp *intel_dp) > static int intel_dp_init_lttpr_phys(struct intel_dp *intel_dp, const u8 dpcd[DP_RECEIVER_CAP_SIZE]) > { > int lttpr_count; > + int ret; > > if (!intel_dp_read_lttpr_common_caps(intel_dp, dpcd)) > return 0; > @@ -172,22 +170,8 @@ static int intel_dp_init_lttpr_phys(struct intel_dp *intel_dp, const u8 dpcd[DP_ > return lttpr_count; > } > > - /* > - * See DP Standard v2.0 3.6.6.1. about the explicit disabling of > - * non-transparent mode and the disable->enable non-transparent mode > - * sequence. > - */ > - intel_dp_set_lttpr_transparent_mode(intel_dp, true); > - > - /* > - * In case of unsupported number of LTTPRs or failing 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_ > goto out_reset_lttpr_count; > } > > + intel_dp_set_lttpr_transparent_mode(intel_dp, false); > + I think the code now misses a way to update intel_dp->lttpr_common_caps in a transparent-mode case: intel_dp_set_lttpr_transparent_mode(intel_dp, true). > return lttpr_count; > > out_reset_lttpr_count: > > -- > 2.34.1 >
On 25-01-03 20:09:42, Dmitry Baryshkov wrote: > On Fri, Jan 03, 2025 at 02:58:17PM +0200, Abel Vesa wrote: > > LTTPRs operating modes are defined by the DisplayPort standard and the > > generic framework now provides a helper to switch between them, which > > is handling the explicit disabling of non-transparent mode and its > > disable->enable sequence mentioned in the DP Standard v2.0 section > > 3.6.6.1. > > > > So use the new drm generic helper instead as it makes the code a bit > > cleaner. > > > > Acked-by: Imre Deak <imre.deak@intel.com> > > Signed-off-by: Abel Vesa <abel.vesa@linaro.org> > > --- > > .../gpu/drm/i915/display/intel_dp_link_training.c | 24 +++++----------------- > > 1 file changed, 5 insertions(+), 19 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.c b/drivers/gpu/drm/i915/display/intel_dp_link_training.c > > index 8b1977cfec503c70f07af716ee2c00e7605c6adf..c5bad311edf7b9a5cebb633b9e9692bae397f9ed 100644 > > --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c > > +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c > > @@ -119,9 +119,6 @@ intel_dp_set_lttpr_transparent_mode(struct intel_dp *intel_dp, bool enable) > > u8 val = enable ? DP_PHY_REPEATER_MODE_TRANSPARENT : > > DP_PHY_REPEATER_MODE_NON_TRANSPARENT; > > > > - if (drm_dp_dpcd_write(&intel_dp->aux, DP_PHY_REPEATER_MODE, &val, 1) != 1) > > - return false; > > - > > intel_dp->lttpr_common_caps[DP_PHY_REPEATER_MODE - > > DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV] = val; > > > > @@ -146,6 +143,7 @@ static bool intel_dp_lttpr_transparent_mode_enabled(struct intel_dp *intel_dp) > > static int intel_dp_init_lttpr_phys(struct intel_dp *intel_dp, const u8 dpcd[DP_RECEIVER_CAP_SIZE]) > > { > > int lttpr_count; > > + int ret; > > > > if (!intel_dp_read_lttpr_common_caps(intel_dp, dpcd)) > > return 0; > > @@ -172,22 +170,8 @@ static int intel_dp_init_lttpr_phys(struct intel_dp *intel_dp, const u8 dpcd[DP_ > > return lttpr_count; > > } > > > > - /* > > - * See DP Standard v2.0 3.6.6.1. about the explicit disabling of > > - * non-transparent mode and the disable->enable non-transparent mode > > - * sequence. > > - */ > > - intel_dp_set_lttpr_transparent_mode(intel_dp, true); > > - > > - /* > > - * In case of unsupported number of LTTPRs or failing 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_ > > goto out_reset_lttpr_count; > > } > > > > + intel_dp_set_lttpr_transparent_mode(intel_dp, false); > > + > > I think the code now misses a way to update intel_dp->lttpr_common_caps > in a transparent-mode case: > intel_dp_set_lttpr_transparent_mode(intel_dp, true). It is being called if the drm_dp_lttpr_init() returns a non-zero value, but that is not part of the diff here. > > > return lttpr_count; > > > > out_reset_lttpr_count: > > > > -- > > 2.34.1 > > > > -- > With best wishes > Dmitry
diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.c b/drivers/gpu/drm/i915/display/intel_dp_link_training.c index 8b1977cfec503c70f07af716ee2c00e7605c6adf..c5bad311edf7b9a5cebb633b9e9692bae397f9ed 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c @@ -119,9 +119,6 @@ intel_dp_set_lttpr_transparent_mode(struct intel_dp *intel_dp, bool enable) u8 val = enable ? DP_PHY_REPEATER_MODE_TRANSPARENT : DP_PHY_REPEATER_MODE_NON_TRANSPARENT; - if (drm_dp_dpcd_write(&intel_dp->aux, DP_PHY_REPEATER_MODE, &val, 1) != 1) - return false; - intel_dp->lttpr_common_caps[DP_PHY_REPEATER_MODE - DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV] = val; @@ -146,6 +143,7 @@ static bool intel_dp_lttpr_transparent_mode_enabled(struct intel_dp *intel_dp) static int intel_dp_init_lttpr_phys(struct intel_dp *intel_dp, const u8 dpcd[DP_RECEIVER_CAP_SIZE]) { int lttpr_count; + int ret; if (!intel_dp_read_lttpr_common_caps(intel_dp, dpcd)) return 0; @@ -172,22 +170,8 @@ static int intel_dp_init_lttpr_phys(struct intel_dp *intel_dp, const u8 dpcd[DP_ return lttpr_count; } - /* - * See DP Standard v2.0 3.6.6.1. about the explicit disabling of - * non-transparent mode and the disable->enable non-transparent mode - * sequence. - */ - intel_dp_set_lttpr_transparent_mode(intel_dp, true); - - /* - * In case of unsupported number of LTTPRs or failing 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_ goto out_reset_lttpr_count; } + intel_dp_set_lttpr_transparent_mode(intel_dp, false); + return lttpr_count; out_reset_lttpr_count: