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Message-ID: <29584061-a7e9-5db4-a024-eaf7774a03dd@quicinc.com>
Date:   Wed, 27 Sep 2023 13:01:40 -0700
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Subject: Re: [PATCH v7 09/33] ASoC: qdsp6: q6afe: Increase APR timeout
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To:     Mark Brown <broonie@kernel.org>
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References: <20230921214843.18450-1-quic_wcheng@quicinc.com>
 <20230921214843.18450-10-quic_wcheng@quicinc.com>
 <ZRRBIa+bVSqTHprO@finisterre.sirena.org.uk>
From:   Wesley Cheng <quic_wcheng@quicinc.com>
In-Reply-To: <ZRRBIa+bVSqTHprO@finisterre.sirena.org.uk>
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Hi Mark,

On 9/27/2023 7:50 AM, Mark Brown wrote:
> On Thu, Sep 21, 2023 at 02:48:19PM -0700, Wesley Cheng wrote:
>> For USB offloading situations, the AFE port start command will result in a
>> QMI handshake between the Q6DSP and the main processor.  Depending on if
>> the USB bus is suspended, this routine would require more time to complete,
>> as resuming the USB bus has some overhead associated with it.  Increase the
>> timeout to 3s to allow for sufficient time for the USB QMI stream enable
>> handshake to complete.
> 
> ...
> 
>> -#define TIMEOUT_MS 1000
>> +#define TIMEOUT_MS 3000
> 
> That seems worryingly large but if it's what the hardware/firmware needs
> I guess there's nothing doing - even the 1s that's being replaced would
> be nasty if we ever actually hit it.

I may have gone overkill with the delay, but when I measured the 
duration of the AFE start command it took ~1.5-2s.  It has to also 
account for the overhead within handling the USB QMI request in the 
qc_audio_offload driver.

Thanks
Wesley Cheng