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From:   Stephen Boyd <swboyd@chromium.org>
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Date:   Mon, 24 May 2021 19:10:08 +0000
Message-ID: <CAE-0n507ahZLDbtfo-s+goBd5kUqBQ9hTqeoCvk1mNb9=XB5wg@mail.gmail.com>
Subject: Re: [PATCH v6] drm/msm/dp: handle irq_hpd with sink_count = 0 correctly
To:     Kuogee Hsieh <khsieh@codeaurora.org>, agross@kernel.org,
        bjorn.andersson@linaro.org, robdclark@gmail.com, sean@poorly.run,
        vkoul@kernel.org
Cc:     abhinavk@codeaurora.org, aravindh@codeaurora.org,
        linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org
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Quoting Kuogee Hsieh (2021-05-21 15:25:30)
> irq_hpd interrupt should be handled after dongle plugged in and
> before dongle unplugged. Hence irq_hpd interrupt is enabled at
> the end of the plugin handle and disabled at the beginning of
> unplugged handle. Current irq_hpd with sink_count = 0 is wrongly
> handled same as the dongle unplugged which tears down the mainlink
> and disables the phy. This patch fixes this problem by only tearing
> down the mainlink but keeping phy enabled at irq_hpd with
> sink_count = 0 handle so that next irq_hpd with sink_count =1 can be
> handled by setup mainlink only. This patch also set dongle into D3
> (power off) state at end of handling irq_hpd with sink_count = 0.
>
> Changes in v2:
> -- add ctrl->phy_Power_count
>
> Changes in v3:
> -- del ctrl->phy_Power_count
> -- add phy_power_off to dp_ctrl_off_link_stream()
>
> Changes in v4:
> -- return immediately if clock disable failed at dp_ctrl_off_link_stream()
>
> Changes in v5:
> -- set dongle to D3 (power off) state at dp_ctrl_off_link_stream()
>
> Changes in v6:
> -- add Fixes tag
>
> Fixes: 94e58e2d06e3 ("drm/msm/dp: reset dp controller only at boot up and pm_resume")
>
> Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>
> ---

Tested-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>