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Date:   Wed, 24 May 2023 11:46:21 +0000
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From:   "Leonard Lausen" <leonard@lausen.nl>
Message-ID: <3a11741c9cc699e178f9b705a34342add03ea0df@lausen.nl>
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Subject: Re: [PATCH v6] drm/msm/dp: enable HDP plugin/unplugged interrupts at
 hpd_enable/disable
To:     "Kuogee Hsieh" <quic_khsieh@quicinc.com>,
        dri-devel@lists.freedesktop.org, robdclark@gmail.com,
        sean@poorly.run, swboyd@chromium.org, dianders@chromium.org,
        vkoul@kernel.org, daniel@ffwll.ch, airlied@gmail.com,
        agross@kernel.org, dmitry.baryshkov@linaro.org,
        andersson@kernel.org, regressions@lists.linux.dev
Cc:     "Kuogee Hsieh" <quic_khsieh@quicinc.com>,
        quic_abhinavk@quicinc.com, quic_jesszhan@quicinc.com,
        quic_sbillaka@quicinc.com, marijn.suijten@somainline.org,
        freedreno@lists.freedesktop.org, linux-arm-msm@vger.kernel.org,
        linux-kernel@vger.kernel.org
In-Reply-To: <1684878756-17830-1-git-send-email-quic_khsieh@quicinc.com>
References: <1684878756-17830-1-git-send-email-quic_khsieh@quicinc.com>
Precedence: bulk

Kuogee Hsieh <quic_khsieh@quicinc.com> writes:
> The internal_hpd flag is set to true by dp_bridge_hpd_enable() and set =
to
> false by dp_bridge_hpd_disable() to handle GPIO pinmuxed into DP contro=
ller
> case. HDP related interrupts can not be enabled until internal_hpd is s=
et
> to true. At current implementation dp_display_config_hpd() will initial=
ize
> DP host controller first followed by enabling HDP related interrupts if
> internal_hpd was true at that time. Enable HDP related interrupts depen=
ds on
> internal_hpd status may leave system with DP driver host is in running =
state
> but without HDP related interrupts being enabled. This will prevent ext=
ernal
> display from being detected. Eliminated this dependency by moving HDP r=
elated
> interrupts enable/disable be done at dp_bridge_hpd_enable/disable() dir=
ectly
> regardless of internal_hpd status.
>
> Changes in V3:
> -- dp_catalog_ctrl_hpd_enable() and dp_catalog_ctrl_hpd_disable()
> -- rewording ocmmit text
>
> Changes in V4:
> -- replace dp_display_config_hpd() with dp_display_host_start()
> -- move enable_irq() at dp_display_host_start();
>
> Changes in V5:
> -- replace dp_display_host_start() with dp_display_host_init()
>
> Changes in V6:
> -- squash remove enable_irq() and disable_irq()
>
> Fixes: cd198caddea7 ("drm/msm/dp: Rely on hpd_enable/disable callbacks"=
)
> Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>

Cherry-picked on top of v6.3.3 and verified fixes the USB-C DP
regression on sc7180 lazor. Thank you!

Tested-by: Leonard Lausen <leonard@lausen.nl> # on sc7180 lazor