linux-kernel - Re: [PATCH v4] drm/msm/dp: enable HDP plugin/unplugged interrupts at hpd

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Message-ID: <16c5ddb7-f5a4-d70b-ce0c-32aa6674fc98@linaro.org>
Date:   Tue, 23 May 2023 15:34:13 +0300
From:   Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To:     Bjorn Andersson <andersson@...nel.org>,
        Kuogee Hsieh <quic_khsieh@...cinc.com>
Cc:     robdclark@...il.com, sean@...rly.run, swboyd@...omium.org,
        dianders@...omium.org, vkoul@...nel.org, daniel@...ll.ch,
        airlied@...il.com, agross@...nel.org,
        marijn.suijten@...ainline.org, quic_abhinavk@...cinc.com,
        quic_jesszhan@...cinc.com, quic_sbillaka@...cinc.com,
        freedreno@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org,
        linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4] drm/msm/dp: enable HDP plugin/unplugged interrupts at
 hpd_enable/disable

On 23/05/2023 15:35, Bjorn Andersson wrote:
> On Mon, May 22, 2023 at 04:02:45PM -0700, Kuogee Hsieh wrote:
>> 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 controller
>> case. HDP related interrupts can not be enabled until internal_hpd is set
>> to true. At current implementation dp_display_config_hpd() will initialize
>> DP host controller first followed by enabling HDP related interrupts if
>> internal_hpd was true at that time. Enable HDP related interrupts depends 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 external
>> display from being detected. Eliminated this dependency by moving HDP related
>> interrupts enable/disable be done at dp_bridge_hpd_enable/disable() directly
>> 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();
> 
> I think what Dmitry was asking for was that you remove the disable_irq()
> from dp_display_request_irq(), but perhaps I missed some argumentation
> for why that can't/shouldn't be done?
> 

Yes, I was asking to get it removed. Kuogee, is there any reason for 
keeping the enable_irq() / disable_irq() calls?

-- 
With best wishes
Dmitry