linux-kernel - Re: [PATCH 1/2] ASoC: max98090: Add master clock handling

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 22 May 2014 09:51:38 -0600
From:	Stephen Warren <swarren@...dotorg.org>
To:	Tushar Behera <tushar.behera@...aro.org>,
	alsa-devel@...a-project.org, linux-kernel@...r.kernel.org,
	devicetree@...r.kernel.org
CC:	tiwai@...e.de, perex@...ex.cz, broonie@...nel.org,
	dianders@...omium.org, jerry.wong@...imintegrated.com
Subject: Re: [PATCH 1/2] ASoC: max98090: Add master clock handling

On 05/22/2014 03:17 AM, Tushar Behera wrote:
> If master clock is provided through device tree, then update
> the master clock frequency during set_sysclk.
> 
> Documentation has been updated to reflect the change.

> diff --git a/sound/soc/codecs/max98090.c b/sound/soc/codecs/max98090.c

> @@ -1929,6 +1930,11 @@ static int max98090_dai_set_sysclk(struct snd_soc_dai *dai,
>  	if (freq == max98090->sysclk)
>  		return 0;
>  
> +	if (!IS_ERR(max98090->mclk)) {
> +		freq = clk_round_rate(max98090->mclk, freq);
> +		clk_set_rate(max98090->mclk, freq);
> +	}

What are the intended semantics of set_sysclk()?
sound/soc/tegra/tegra_wm98090.c assumes that set_sysclk() is a
notification to the CODEC driver to tell it what rate the MCLK input is
set to (the rate is set before calling set_sysclk), whereas the code
above assumes that this function is to tell the CODEC to somehow
configure its input clock to be a particular rate. I have a feeling the
code above might fail on Tegra.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/