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]
Message-ID: <da74d276-b028-448b-bb28-295de49dbcda@sirena.org.uk>
Date: Fri, 17 May 2024 12:17:20 +0100
From: Mark Brown <broonie@...nel.org>
To: Elinor Montmasson <elinor.montmasson@...oirfairelinux.com>
Cc: Liam Girdwood <lgirdwood@...il.com>, Rob Herring <robh+dt@...nel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
	Conor Dooley <conor+dt@...nel.org>,
	shengjiu wang <shengjiu.wang@...il.com>,
	Xiubo Lee <Xiubo.Lee@...il.com>, Fabio Estevam <festevam@...il.com>,
	Nicolin Chen <nicoleotsuka@...il.com>,
	Jaroslav Kysela <perex@...ex.cz>, Takashi Iwai <tiwai@...e.com>,
	linux-sound <linux-sound@...r.kernel.org>,
	devicetree <devicetree@...r.kernel.org>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	alsa-devel <alsa-devel@...a-project.org>,
	linuxppc-dev <linuxppc-dev@...ts.ozlabs.org>
Subject: Re: [PATCHv4 7/9] ASoC: fsl-asoc-card: add DT clock "cpu_sysclk"
 with generic codec

On Fri, May 17, 2024 at 05:05:35AM -0400, Elinor Montmasson wrote:
> From: "Mark Brown" <broonie@...nel.org>
> > On Wed, May 15, 2024 at 03:54:09PM +0200, Elinor Montmasson wrote:

> >> +		struct clk *cpu_sysclk = clk_get(&pdev->dev, "cpu_sysclk");
> >> +		if (!IS_ERR(cpu_sysclk)) {
> >> +			priv->cpu_priv.sysclk_freq[TX] = clk_get_rate(cpu_sysclk);
> >> +			priv->cpu_priv.sysclk_freq[RX] = priv->cpu_priv.sysclk_freq[TX];
> >> +			clk_put(cpu_sysclk);
> >> +		}

> > I don't really understand the goal here - this is just reading whatever
> > frequency happens to be set in the hardware when the driver starts up
> > which if nothing else seems rather fragile?

> The driver allow to set the sysclk frequency
> of the CPU DAI through `priv->cpu_priv.sysclk_freq` when calling
> `fsl_asoc_card_hw_params()`.
> Currently it is hard-coded per use-case in the driver.

> My reasoning was that with a generic codec/compatible, there might
> be use-cases needing to use this parameter, so I exposed it here via DT.

> Is it a bad idea to expose this parameter ? This is not a requirement for the
> driver to work, most of the current compatibles do not use this parameter.
> It is currently used only for `fsl,imx-audio-cs42888`.
> In that case I can remove this commit.

I'm having a hard time connecting your reply here with my comment.  This
isn't as far as I can see allowing the frequency to be explicitly
configured, it's just using whatever value happens to be programmed in
the clock when the driver starts.

Download attachment "signature.asc" of type "application/pgp-signature" (489 bytes)

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ