| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <CAGXv+5FrUPUg_SsRz6LrW_K_C7By2tSCQ9W_MNJr8XCOcn7gLA@mail.gmail.com>
Date: Thu, 6 Apr 2023 16:20:48 +0800
From: Chen-Yu Tsai <wenst@...omium.org>
To: AngeloGioacchino Del Regno
<angelogioacchino.delregno@...labora.com>
Cc: chunkuang.hu@...nel.org, p.zabel@...gutronix.de, airlied@...il.com,
daniel@...ll.ch, matthias.bgg@...il.com,
dri-devel@...ts.freedesktop.org,
linux-mediatek@...ts.infradead.org, linux-kernel@...r.kernel.org,
linux-arm-kernel@...ts.infradead.org, kernel@...labora.com
Subject: Re: [PATCH v3 2/9] drm/mediatek: dp: Move AUX and panel poweron/off
sequence to function
On Tue, Apr 4, 2023 at 6:48 PM AngeloGioacchino Del Regno
<angelogioacchino.delregno@...labora.com> wrote:
>
> 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.
>
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>
> ---
> 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 84f82cc68672..76ea94167531 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dp.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dp.c
> @@ -1253,6 +1253,29 @@ 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,
> @@ -1937,16 +1960,9 @@ 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);
I suspect the original code was somewhat wrong already? We shouldn't need
to pull the panel out of standby just for HPD or reading EDID.
This driver probably needs a lot more cleanup. :/
ChenYu
> - 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
> @@ -1958,16 +1974,8 @@ 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;
> }
> @@ -1983,15 +1991,7 @@ 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);
> }
>
> /* eDP panels aren't removable, so we can return a cached EDID. */
> @@ -2015,15 +2015,7 @@ 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);
> }
>
> @@ -2188,15 +2180,7 @@ 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);
> --
> 2.40.0
>
Powered by blists - more mailing lists