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From: Mark Brown <broonie@kernel.org>
To: Richard Fitzgerald <rf@opensource.cirrus.com>
Cc: alsa-devel@alsa-project.org, patches@opensource.cirrus.com,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 04/12] ASoC: cs42l42: Don't reconfigure the PLL while it is running
Date: Wed, 11 Aug 2021 12:56:37 +0100	[thread overview]
Message-ID: <20210811115637.GA4167@sirena.org.uk> (raw)
In-Reply-To: <c194004a-2a22-5354-9042-3ce811236319@opensource.cirrus.com>

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On Tue, Aug 10, 2021 at 05:27:45PM +0100, Richard Fitzgerald wrote:
> On 10/08/2021 16:49, Mark Brown wrote:

> > Shouldn't the PLL code be noticing problematic attempts to reconfigure
> > the PLL while it's active rather than the individual callers?

> It's wrong for a hw_params() for one stream to try to configure the PLL
> when the other stream has already called hw_params(), configured the PLL
> and started it. E.g. if you started a PLAYBACK, configured and
> started everything, then got another hw_params() for the CAPTURE.

> cs42l42_pll_config() could check whether it is already running and skip
> configuration in that case, but that seems to me a rather opaque
> implementation. In my opinion this doesn't really fall into the case of
> ignoring-bad-stuff-to-be-helpful (like free() accepting a NULL).

This doesn't treat the situation as an error though, it just ignores it,
and there's nothing to stop _pll_config() generating a warning if that
makes sense.

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  reply	other threads:[~2021-08-11 11:56 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-10 15:37 [PATCH 00/12] ASoC: cs42l42: Series of bugfixes and improvements Richard Fitzgerald
2021-08-10 15:37 ` [PATCH 01/12] ASoC: cs42l42: Use PLL for SCLK > 12.188MHz Richard Fitzgerald
2021-08-10 15:37 ` [PATCH 02/12] ASoC: cs42l42: Don't claim to support 192k Richard Fitzgerald
2021-08-10 15:37 ` [PATCH 03/12] ASoC: cs42l42: Always configure both ASP TX channels Richard Fitzgerald
2021-08-10 15:37 ` [PATCH 04/12] ASoC: cs42l42: Don't reconfigure the PLL while it is running Richard Fitzgerald
2021-08-10 15:49   ` Mark Brown
2021-08-10 16:27     ` Richard Fitzgerald
2021-08-11 11:56       ` Mark Brown [this message]
2021-08-11 12:21         ` Richard Fitzgerald
2021-08-11 14:41           ` Mark Brown
2021-08-11 10:56     ` Richard Fitzgerald
2021-08-10 15:37 ` [PATCH 05/12] ASoC: cs42l42: Set correct SRC MCLK Richard Fitzgerald
2021-08-10 15:37 ` [PATCH 06/12] ASoC: cs42l42: Mark OSC_SWITCH_STATUS register volatile Richard Fitzgerald
2021-08-10 15:37 ` [PATCH 07/12] ASoC: cs42l42: Allow time for HP/ADC to power-up after enable Richard Fitzgerald
2021-08-10 15:37 ` [PATCH 08/12] ASoC: cs42l42: Prevent NULL pointer deref in interrupt handler Richard Fitzgerald
2021-08-10 15:37 ` [PATCH 09/12] ASoC: cs42l42: Remove runtime_suspend/runtime_resume callbacks Richard Fitzgerald
2021-08-10 15:37 ` [PATCH 10/12] ASoC: cs42l42: Remove redundant pll_divout member Richard Fitzgerald
2021-08-10 15:37 ` [PATCH 11/12] ASoC: cs42l42: Add HP Volume Scale control Richard Fitzgerald
2021-08-10 15:37 ` [PATCH 12/12] ASoC: cs42l42: Add control for audio slow-start switch Richard Fitzgerald

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