Re: [PATCH v5 01/10] drm/mediatek: dp: Move AUX and panel poweron/off sequence to function

From: Chen-Yu Tsai
Date: Tue Jul 18 2023 - 03:41:35 EST

Hi CK,

On Tue, Jul 18, 2023 at 3:40 PM CK Hu (胡俊光) <ck.hu@xxxxxxxxxxxx> wrote:
>
> Hi, Angelo:
>
> On Thu, 2023-07-13 at 11:01 +0200, AngeloGioacchino Del Regno wrote:
> >
> > External email : Please do not click links or open attachments until
> > you have verified the sender or the content.
> > Everytime we run bridge detection and/or EDID read we run a poweron
> > and poweroff sequence for both the AUX and the panel; moreover, this
> > is also done when enabling the bridge in the .atomic_enable()
> > callback.
> >
> > Move this power on/off sequence to a new mtk_dp_aux_panel_poweron()
> > function as to commonize it.
> > Note that, before this commit, in mtk_dp_bridge_atomic_enable() only
> > the AUX was getting powered on but the panel was left powered off if
> > the DP cable wasn't plugged in while now we unconditionally send a D0
> > request and this is done for two reasons:
> > - First, whether this request fails or not, it takes the same time
> > and anyway the DP hardware won't produce any error (or, if it
> > does, it's ignorable because it won't block further commands)
> > - Second, training the link between a sleeping/standby/unpowered
> > display makes little sense.
>
> Reviewed-by: CK Hu <ck.hu@xxxxxxxxxxxx>

There is a v6 already.

> >
> > Signed-off-by: AngeloGioacchino Del Regno <
> > angelogioacchino.delregno@xxxxxxxxxxxxx>
> > Tested-by: Chen-Yu Tsai <wenst@xxxxxxxxxxxx>
> > ---
> > drivers/gpu/drm/mediatek/mtk_dp.c | 76 ++++++++++++-----------------
> > --
> > 1 file changed, 30 insertions(+), 46 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c
> > b/drivers/gpu/drm/mediatek/mtk_dp.c
> > index 64eee77452c0..8b7ded1746f3 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_dp.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_dp.c
> > @@ -1251,6 +1251,29 @@ static void mtk_dp_audio_mute(struct mtk_dp
> > *mtk_dp, bool mute)
> > val[2], AU_TS_CFG_DP_ENC0_P0_MASK);
> > }
> >
> > +static void mtk_dp_aux_panel_poweron(struct mtk_dp *mtk_dp, bool
> > pwron)
> > +{
> > + if (pwron) {
> > + /* power on aux */
> > + mtk_dp_update_bits(mtk_dp, MTK_DP_TOP_PWR_STATE,
> > + DP_PWR_STATE_BANDGAP_TPLL_LANE,
> > + DP_PWR_STATE_MASK);
> > +
> > + /* power on panel */
> > + drm_dp_dpcd_writeb(&mtk_dp->aux, DP_SET_POWER,
> > DP_SET_POWER_D0);
> > + usleep_range(2000, 5000);
> > + } else {
> > + /* power off panel */
> > + drm_dp_dpcd_writeb(&mtk_dp->aux, DP_SET_POWER,
> > DP_SET_POWER_D3);
> > + usleep_range(2000, 3000);
> > +
> > + /* power off aux */
> > + mtk_dp_update_bits(mtk_dp, MTK_DP_TOP_PWR_STATE,
> > + DP_PWR_STATE_BANDGAP_TPLL,
> > + DP_PWR_STATE_MASK);
> > + }
> > +}
> > +
> > static void mtk_dp_power_enable(struct mtk_dp *mtk_dp)
> > {
> > mtk_dp_update_bits(mtk_dp, MTK_DP_TOP_RESET_AND_PROBE,
> > @@ -1936,16 +1959,9 @@ static enum drm_connector_status
> > mtk_dp_bdg_detect(struct drm_bridge *bridge)
> > if (!mtk_dp->train_info.cable_plugged_in)
> > return ret;
> >
> > - if (!enabled) {
> > - /* power on aux */
> > - mtk_dp_update_bits(mtk_dp, MTK_DP_TOP_PWR_STATE,
> > - DP_PWR_STATE_BANDGAP_TPLL_LANE,
> > - DP_PWR_STATE_MASK);
> > + if (!enabled)
> > + mtk_dp_aux_panel_poweron(mtk_dp, true);
> >
> > - /* power on panel */
> > - drm_dp_dpcd_writeb(&mtk_dp->aux, DP_SET_POWER,
> > DP_SET_POWER_D0);
> > - usleep_range(2000, 5000);
> > - }
> > /*
> > * Some dongles still source HPD when they do not connect to
> > any
> > * sink device. To avoid this, we need to read the sink count
> > @@ -1957,16 +1973,8 @@ static enum drm_connector_status
> > mtk_dp_bdg_detect(struct drm_bridge *bridge)
> > if (DP_GET_SINK_COUNT(sink_count))
> > ret = connector_status_connected;
> >
> > - if (!enabled) {
> > - /* power off panel */
> > - drm_dp_dpcd_writeb(&mtk_dp->aux, DP_SET_POWER,
> > DP_SET_POWER_D3);
> > - usleep_range(2000, 3000);
> > -
> > - /* power off aux */
> > - mtk_dp_update_bits(mtk_dp, MTK_DP_TOP_PWR_STATE,
> > - DP_PWR_STATE_BANDGAP_TPLL,
> > - DP_PWR_STATE_MASK);
> > - }
> > + if (!enabled)
> > + mtk_dp_aux_panel_poweron(mtk_dp, false);
> >
> > return ret;
> > }
> > @@ -1982,15 +1990,7 @@ static struct edid *mtk_dp_get_edid(struct
> > drm_bridge *bridge,
> >
> > if (!enabled) {
> > drm_atomic_bridge_chain_pre_enable(bridge, connector-
> > >state->state);
> > -
> > - /* power on aux */
> > - mtk_dp_update_bits(mtk_dp, MTK_DP_TOP_PWR_STATE,
> > - DP_PWR_STATE_BANDGAP_TPLL_LANE,
> > - DP_PWR_STATE_MASK);
> > -
> > - /* power on panel */
> > - drm_dp_dpcd_writeb(&mtk_dp->aux, DP_SET_POWER,
> > DP_SET_POWER_D0);
> > - usleep_range(2000, 5000);
> > + mtk_dp_aux_panel_poweron(mtk_dp, true);
> > }
> >
> > new_edid = drm_get_edid(connector, &mtk_dp->aux.ddc);
> > @@ -2010,15 +2010,7 @@ static struct edid *mtk_dp_get_edid(struct
> > drm_bridge *bridge,
> > }
> >
> > if (!enabled) {
> > - /* power off panel */
> > - drm_dp_dpcd_writeb(&mtk_dp->aux, DP_SET_POWER,
> > DP_SET_POWER_D3);
> > - usleep_range(2000, 3000);
> > -
> > - /* power off aux */
> > - mtk_dp_update_bits(mtk_dp, MTK_DP_TOP_PWR_STATE,
> > - DP_PWR_STATE_BANDGAP_TPLL,
> > - DP_PWR_STATE_MASK);
> > -
> > + mtk_dp_aux_panel_poweron(mtk_dp, false);
> > drm_atomic_bridge_chain_post_disable(bridge, connector-
> > >state->state);
> > }
> >
> > @@ -2178,15 +2170,7 @@ static void mtk_dp_bridge_atomic_enable(struct
> > drm_bridge *bridge,
> > return;
> > }
> >
> > - /* power on aux */
> > - mtk_dp_update_bits(mtk_dp, MTK_DP_TOP_PWR_STATE,
> > - DP_PWR_STATE_BANDGAP_TPLL_LANE,
> > - DP_PWR_STATE_MASK);
> > -
> > - if (mtk_dp->train_info.cable_plugged_in) {
> > - drm_dp_dpcd_writeb(&mtk_dp->aux, DP_SET_POWER,
> > DP_SET_POWER_D0);
> > - usleep_range(2000, 5000);
> > - }
> > + mtk_dp_aux_panel_poweron(mtk_dp, true);
> >
> > /* Training */
> > ret = mtk_dp_training(mtk_dp);
> > --
> > 2.40.1