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Message-ID: <d41e29a9-5da6-3843-5018-9674e7d56505@linaro.org>
Date:   Thu, 15 Dec 2022 23:15:53 +0200
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Subject: Re: [PATCH v2] drm/msm/dp: do not complete dp_aux_cmd_fifo_tx() if
 irq is not for aux transfer
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To:     Stephen Boyd <swboyd@chromium.org>,
        Kuogee Hsieh <quic_khsieh@quicinc.com>, agross@kernel.org,
        airlied@gmail.com, andersson@kernel.org, daniel@ffwll.ch,
        dianders@chromium.org, robdclark@gmail.com, sean@poorly.run,
        vkoul@kernel.org
Cc:     quic_abhinavk@quicinc.com, quic_sbillaka@quicinc.com,
        freedreno@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
        linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org
References: <1671129159-31105-1-git-send-email-quic_khsieh@quicinc.com>
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 <CAE-0n53bREwEMV4aP=ySPuPP8mMbDr=Unbjw_bW0MNN7hTsWRw@mail.gmail.com>
From:   Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
In-Reply-To: <CAE-0n53bREwEMV4aP=ySPuPP8mMbDr=Unbjw_bW0MNN7hTsWRw@mail.gmail.com>
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On 15/12/2022 22:10, Stephen Boyd wrote:
> Quoting Dmitry Baryshkov (2022-12-15 10:46:42)
>> On 15/12/2022 20:32, Kuogee Hsieh wrote:
>>>        if (!aux->cmd_busy)
>>>                return;
>>>
>>>        if (aux->native)
>>> -             dp_aux_native_handler(aux, isr);
>>> +             ret = dp_aux_native_handler(aux, isr);
>>>        else
>>> -             dp_aux_i2c_handler(aux, isr);
>>> +             ret = dp_aux_i2c_handler(aux, isr);
>>>
>>> -     complete(&aux->comp);
>>> +     if (ret == IRQ_HANDLED)
>>> +             complete(&aux->comp);
>>
>> Can you just move the complete() into the individual handling functions?
>> Then you won't have to return the error code from dp_aux_*_handler() at
>> all. You can check `isr' in that function and call complete if there was
>> any error.
> 
> I'd prefer we apply my patch and pass the irqreturn_t variable to the
> caller of this function so spurious irqs are shutdown. Should I send it
> as a proper patch?

I'm for handling the spurious IRQs in a proper way. However I believe 
that it's not related to the issue Kuogee is trying to fix.

Thus I think we should have two separate patches: one fixing the EDID 
corruption issue (for which the proper fix is !isr check, IIUC) and the 
irqreturn_t. And for the irqreturn_t it might be beneficial to move 
complete() call to the dp_aux_foo_handler(). Or might be not. That would 
depend on the patch itself.


-- 
With best wishes
Dmitry