linux-kernel - Re: Odroid-XU4 sound issue after suspend-resume

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Message-ID: <b850da41-fd72-ec0a-52bd-4de558dd87f2@samsung.com>
Date:   Wed, 7 Aug 2019 18:35:50 +0200
From:   Sylwester Nawrocki <s.nawrocki@...sung.com>
To:     Jaafar Ali <jaafarkhalaf@...il.com>
Cc:     linux-samsung-soc@...r.kernel.org, linux-kernel@...r.kernel.org,
        kgene@...nel.org, Krzysztof Kozlowski <krzk@...nel.org>,
        sam@...nborg.org, linux-clk@...r.kernel.org
Subject: Re: Odroid-XU4 sound issue after suspend-resume

On 8/7/19 10:22, Sylwester Nawrocki wrote:
> On 8/5/19 15:27, Jaafar Ali wrote:
>> Dear All,
>> Kernel 5.3-rc1
>> OS: ubuntu 18.04
>> Hardware: Odroid-XU4
>> The sound of Odroid-XU4 after suspend/resume cycle is choppy and slow. 
>> I have found a workaround, the I2SMOD register value should be set to 
>> zero after resume to force using internal codec clock (cdclkcon bit = 0),
>> also the rclk_srcrate which is obtained from the function 
>> *clk_get_rate(rclksrc) *inside *hw_params* function is not correct and 
>> must be divided by 2 to obtain proper value, i2s_resume function 
>> is modified to:
>>
>> static int i2s_resume(struct snd_soc_dai *dai)
>> {
>>         struct samsung_i2s_priv *priv = dev_get_drvdata(dai->dev);
>>         priv->suspend_i2smod = 0;//workaround-1 ,
>>         return pm_runtime_force_resume(dai->dev);
>>
>> }
>>
>> inside hw_params function, the rclk_srcrate must be halved to solve 
>> unknown problem of clock shift, so before return from hw_params we 
>> must insert:
>> if(mod == 0){
>> 	priv->rclk_srcrate = priv->rclk_srcrate / 2; //workaround-2, 
>> }
>>
>> With these two workaround sound issue was solved, but I hope we can 
>> get concrete fix.
> Thank you for the bug report. I spent some time on debugging this and
> it turned out that there is a clock mux between EPLL and the audio 
> subsystem which looses its configuration during suspend/resume cycle.
> So we end up with the I2S controller clocked from the main oscillator
> clock (24 MHz) rather than the EPLL (196.608 MHz) after system suspend/
> resume. I will post a patch for clk-exynos5420 driver shortly.

My apologies, I forgot to add you at Cc of related patches, they are 
available at patchwork:
https://patchwork.kernel.org/patch/11082423
https://patchwork.kernel.org/patch/11082427
 
Could you try and test and let me know if that fixes your issue?

-- 
Thanks,
Sylwester