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Message-ID: <06650d56-eed3-73ad-d6b4-6b56a5a70669@linux.intel.com>
Date:   Fri, 25 Feb 2022 09:43:47 -0600
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Subject: Re: [PATCH v2] soundwire: qcom: remove redundant wait for completion
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To:     Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
        Srinivasa Rao Mandadapu <quic_srivasam@quicinc.com>,
        agross@kernel.org, bjorn.andersson@linaro.org, lgirdwood@gmail.com,
        broonie@kernel.org, robh+dt@kernel.org, quic_plai@quicinc.com,
        bgoswami@codeaurora.org, perex@perex.cz, tiwai@suse.com,
        rohitkr@codeaurora.org, linux-arm-msm@vger.kernel.org,
        alsa-devel@alsa-project.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, swboyd@chromium.org,
        judyhsiao@chromium.org, yung-chuan.liao@linux.intel.com,
        sanyog.r.kale@intel.com
Cc:     Venkata Prasad Potturu <quic_potturu@quicinc.com>
References: <1645800257-27025-1-git-send-email-quic_srivasam@quicinc.com>
 <a99a59eb-cd59-f566-b98d-486c94f32eec@linaro.org>
From:   Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
In-Reply-To: <a99a59eb-cd59-f566-b98d-486c94f32eec@linaro.org>
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On 2/25/22 08:45, Srinivas Kandagatla wrote:
> 
> 
> On 25/02/2022 14:44, Srinivasa Rao Mandadapu wrote:
>> Remove wait_for_completion_timeout from soundwire probe as it seems
>> unnecessary and device enumeration is anyway not happening here,
>> hence this api is blocking till it completes max wait time.
>> Also, as device enumeration event is dependent on wcd938x probe to be
>> completed, its of no use waiting here.
>> Waiting here increasing the boot time almost 4 seconds and impacting
>> other modules like touch screen.
>>
>> Fixes: 06dd96738d618 ("soundwire: qcom: wait for enumeration to be
>> complete in probe")
>>
>> Signed-off-by: Srinivasa Rao Mandadapu <quic_srivasam@quicinc.com>
>> Co-developed-by: Venkata Prasad Potturu <quic_potturu@quicinc.com>
>> Signed-off-by: Venkata Prasad Potturu <quic_potturu@quicinc.com>
> 
> LGTM,
> 
> Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

I don't get the idea, sorry.

If you look at the code, these are the cases where this 'struct
completion' is used

	struct completion enumeration;
	complete(&ctrl->enumeration);
	/* Enable Auto enumeration */
	init_completion(&ctrl->enumeration);
	wait_for_completion_timeout(&ctrl->enumeration,


so if you remove the wait_for_completeion, then you might just as well
remove the whole thing and revert 06dd96738d618

what am I missing?


>> ---
>>   drivers/soundwire/qcom.c | 2 --
>>   1 file changed, 2 deletions(-)
>>
>> diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
>> index 5481341..9a32a24 100644
>> --- a/drivers/soundwire/qcom.c
>> +++ b/drivers/soundwire/qcom.c
>> @@ -1309,8 +1309,6 @@ static int qcom_swrm_probe(struct
>> platform_device *pdev)
>>       }
>>         qcom_swrm_init(ctrl);
>> -    wait_for_completion_timeout(&ctrl->enumeration,
>> -                    msecs_to_jiffies(TIMEOUT_MS));
>>       ret = qcom_swrm_register_dais(ctrl);
>>       if (ret)
>>           goto err_master_add;