From: Michael Walle <michael@walle.cc> To: Mark Brown <broonie@kernel.org> Cc: Sameer Pujar <spujar@nvidia.com>, alsa-devel@alsa-project.org, devicetree@vger.kernel.org, jonathanh@nvidia.com, kuninori.morimoto.gx@renesas.com, linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org, robh@kernel.org, sharadg@nvidia.com, thierry.reding@gmail.com Subject: Re: [PATCH 1/3] ASoC: simple-card-utils: Fix device module clock Date: Thu, 11 Mar 2021 23:11:15 +0100 [thread overview] Message-ID: <f21b87f1afb3eda54b5f00f2d1c146d3@walle.cc> (raw) In-Reply-To: <20210311161558.GG4962@sirena.org.uk> Am 2021-03-11 17:15, schrieb Mark Brown: > On Wed, Mar 10, 2021 at 08:20:28PM +0530, Sameer Pujar wrote: > >> If I read this correctly below is the configuration you need, >> SoC -> MCLK(fixed rate) -> PLL(wm8904) -> PLL output (256 * fs) -> >> sysclk > > For this device for integration with something like simple-audio-card > since there's limited flexibility within the device the simplest thing > would be to not make the internal clocking of the device visible and > just have it figure out how to use the input clock, using the MCLK > directly if possible otherwise using the FLL to generate a suitable > clock. Before this patch, part of this was already happening. That is, simple-audio-card called set_sysclk(samplerate * mclk-fs), then the codec figured out that its mclk was different than the requested sample rate and enabled its FLL to generate the requested sample rate automatically. With this patch applied, simple-audio-card already tries to change mclk, which isn't working in my case (the MCLK isn't generated by a PLL and just supports fixed frequencies) and thus breaks audio. And this patch also propagate to the stable kernels and breaks my board there, too. > The trick is figuring out if it's best to vary the input clock > or to use the FLL to adapt a fixed input clock, For simple-audio-card you can set the "clock" property if you want that clock to be changed/enabled/disabled. But that doesn't seem to be the way to go, at least it was NAKed by Rob for the audio-graph-card. I don't see a way to figure out if MCLK should be controlled by simple-*-card without adding further properties to the device tree. > and of course adapting any existing users if things get changed. To be frank, I don't see that happening. -michael
WARNING: multiple messages have this Message-ID (diff)
From: Michael Walle <michael@walle.cc> To: Mark Brown <broonie@kernel.org> Cc: devicetree@vger.kernel.org, alsa-devel@alsa-project.org, kuninori.morimoto.gx@renesas.com, robh@kernel.org, Sameer Pujar <spujar@nvidia.com>, linux-kernel@vger.kernel.org, jonathanh@nvidia.com, sharadg@nvidia.com, thierry.reding@gmail.com, linux-tegra@vger.kernel.org Subject: Re: [PATCH 1/3] ASoC: simple-card-utils: Fix device module clock Date: Thu, 11 Mar 2021 23:11:15 +0100 [thread overview] Message-ID: <f21b87f1afb3eda54b5f00f2d1c146d3@walle.cc> (raw) In-Reply-To: <20210311161558.GG4962@sirena.org.uk> Am 2021-03-11 17:15, schrieb Mark Brown: > On Wed, Mar 10, 2021 at 08:20:28PM +0530, Sameer Pujar wrote: > >> If I read this correctly below is the configuration you need, >> SoC -> MCLK(fixed rate) -> PLL(wm8904) -> PLL output (256 * fs) -> >> sysclk > > For this device for integration with something like simple-audio-card > since there's limited flexibility within the device the simplest thing > would be to not make the internal clocking of the device visible and > just have it figure out how to use the input clock, using the MCLK > directly if possible otherwise using the FLL to generate a suitable > clock. Before this patch, part of this was already happening. That is, simple-audio-card called set_sysclk(samplerate * mclk-fs), then the codec figured out that its mclk was different than the requested sample rate and enabled its FLL to generate the requested sample rate automatically. With this patch applied, simple-audio-card already tries to change mclk, which isn't working in my case (the MCLK isn't generated by a PLL and just supports fixed frequencies) and thus breaks audio. And this patch also propagate to the stable kernels and breaks my board there, too. > The trick is figuring out if it's best to vary the input clock > or to use the FLL to adapt a fixed input clock, For simple-audio-card you can set the "clock" property if you want that clock to be changed/enabled/disabled. But that doesn't seem to be the way to go, at least it was NAKed by Rob for the audio-graph-card. I don't see a way to figure out if MCLK should be controlled by simple-*-card without adding further properties to the device tree. > and of course adapting any existing users if things get changed. To be frank, I don't see that happening. -michael
next prev parent reply other threads:[~2021-03-11 22:11 UTC|newest] Thread overview: 74+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-02-10 6:43 [PATCH 0/3] Use clocks property in a device node Sameer Pujar 2021-02-10 6:43 ` Sameer Pujar 2021-02-10 6:43 ` [PATCH 1/3] ASoC: simple-card-utils: Fix device module clock Sameer Pujar 2021-02-10 6:43 ` Sameer Pujar 2021-02-11 23:44 ` Kuninori Morimoto 2021-02-11 23:44 ` Kuninori Morimoto 2021-02-14 17:56 ` Sameer Pujar 2021-02-14 17:56 ` Sameer Pujar 2021-02-14 23:25 ` Kuninori Morimoto 2021-02-14 23:25 ` Kuninori Morimoto 2021-03-09 14:41 ` Michael Walle 2021-03-09 14:41 ` Michael Walle 2021-03-09 16:27 ` Sameer Pujar 2021-03-09 16:27 ` Sameer Pujar 2021-03-09 22:30 ` Michael Walle 2021-03-09 22:30 ` Michael Walle 2021-03-10 14:50 ` Sameer Pujar 2021-03-10 14:50 ` Sameer Pujar 2021-03-10 18:14 ` Michael Walle 2021-03-10 18:14 ` Michael Walle 2021-03-10 19:19 ` Sameer Pujar 2021-03-10 19:19 ` Sameer Pujar 2021-03-11 10:27 ` Michael Walle 2021-03-11 10:27 ` Michael Walle 2021-03-11 11:05 ` Sameer Pujar 2021-03-11 11:05 ` Sameer Pujar 2021-03-11 11:16 ` Michael Walle 2021-03-11 11:16 ` Michael Walle 2021-03-11 14:29 ` Sameer Pujar 2021-03-11 14:29 ` Sameer Pujar 2021-03-11 15:43 ` Michael Walle 2021-03-11 15:43 ` Michael Walle 2021-03-11 16:41 ` Mark Brown 2021-03-11 16:41 ` Mark Brown 2021-03-11 16:15 ` Mark Brown 2021-03-11 16:15 ` Mark Brown 2021-03-11 22:11 ` Michael Walle [this message] 2021-03-11 22:11 ` Michael Walle 2021-03-12 11:35 ` Mark Brown 2021-03-12 11:35 ` Mark Brown 2021-03-12 12:01 ` Michael Walle 2021-03-12 12:01 ` Michael Walle 2021-03-12 12:04 ` Mark Brown 2021-03-12 12:04 ` Mark Brown 2021-03-12 12:30 ` Michael Walle 2021-03-12 12:30 ` Michael Walle 2021-03-12 13:46 ` Mark Brown 2021-03-12 13:46 ` Mark Brown 2021-03-15 12:05 ` Michael Walle 2021-03-15 12:05 ` Michael Walle 2021-03-15 15:19 ` Sameer Pujar 2021-03-15 15:19 ` Sameer Pujar 2021-03-15 15:33 ` Michael Walle 2021-03-15 15:33 ` Michael Walle 2021-03-15 15:57 ` Sameer Pujar 2021-03-15 15:57 ` Sameer Pujar 2021-03-15 15:39 ` Mark Brown 2021-03-15 15:39 ` Mark Brown 2021-03-15 17:10 ` Sameer Pujar 2021-03-15 17:10 ` Sameer Pujar 2021-03-15 17:13 ` Michael Walle 2021-03-15 17:13 ` Michael Walle 2021-03-11 16:00 ` Mark Brown 2021-03-11 16:00 ` Mark Brown 2021-03-11 21:34 ` Michael Walle 2021-03-11 21:34 ` Michael Walle 2021-02-10 6:43 ` [PATCH 2/3] Revert "ASoC: audio-graph-card: Add clocks property to endpoint node" Sameer Pujar 2021-02-10 6:43 ` Sameer Pujar 2021-02-11 13:00 ` Mark Brown 2021-02-11 13:00 ` Mark Brown 2021-02-10 6:43 ` [PATCH 3/3] arm64: tegra: Move clocks from RT5658 endpoint to device node Sameer Pujar 2021-02-10 6:43 ` Sameer Pujar 2021-02-11 15:38 ` [PATCH 0/3] Use clocks property in a " Mark Brown 2021-02-11 15:38 ` Mark Brown
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