linux-kernel - Re: [PATCH 2/6] ASoC: ux500: Do not clear state if already idle

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Date:	Wed, 8 May 2013 09:04:48 +0100
From:	Lee Jones <lee.jones@...aro.org>
To:	Fabio Baltieri <fabio.baltieri@...aro.org>
Cc:	Mark Brown <broonie@...nel.org>,
	Liam Girdwood <lgirdwood@...il.com>,
	alsa-devel@...a-project.org, linux-kernel@...r.kernel.org,
	Linus Walleij <linus.walleij@...aro.org>,
	Ola Lilja <ola.o.lilja@...ricsson.com>
Subject: Re: [PATCH 2/6] ASoC: ux500: Do not clear state if already idle

On Wed, 08 May 2013, Fabio Baltieri wrote:

> As enable_msp gets called only after some audio data has been received,
> if the userspace closes the device before sending any data it causes
> ux500_msp_i2s_close to clear device state even if it was not previously
> initialized.
> 
> This in turns leads to some non necessary but harmless writel, but also
   Singular ^

> to decrementing the pinctrl usage counter (pinctrl_rxtx_ref) below zero.
> 
> To prevent this from happening add a condition to skip register and
> pinctrl clear if current msp state is already MSP_STATE_IDLE.
> 
> Signed-off-by: Fabio Baltieri <fabio.baltieri@...aro.org>
> ---
>  sound/soc/ux500/ux500_msp_i2s.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/sound/soc/ux500/ux500_msp_i2s.c b/sound/soc/ux500/ux500_msp_i2s.c
> index a26c6bf..964cfd6 100644
> --- a/sound/soc/ux500/ux500_msp_i2s.c
> +++ b/sound/soc/ux500/ux500_msp_i2s.c
> @@ -638,7 +638,7 @@ int ux500_msp_i2s_close(struct ux500_msp *msp, unsigned int dir)
>  	dev_dbg(msp->dev, "%s: Enter (dir = 0x%01x).\n", __func__, dir);
>  
>  	status = disable_msp(msp, dir);
> -	if (msp->dir_busy == 0) {
> +	if (msp->dir_busy == 0 && msp->msp_state != MSP_STATE_IDLE) {
>  		/* disable sample rate and frame generators */
>  		msp->msp_state = MSP_STATE_IDLE;
>  		writel((readl(msp->registers + MSP_GCR) &

Code looks good though:

Acked-by: Lee Jones <lee.jones@...aro.org>

-- 
Lee Jones
Linaro ST-Ericsson Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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