linux-kernel - Re: [PATCH] mfd: intel-lpss: Do not put device in reset state on suspend

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Date:   Wed, 26 Oct 2016 13:30:23 +0100
From:   Lee Jones <lee.jones@...aro.org>
To:     Azhar Shaikh <azhar.shaikh@...el.com>
Cc:     andriy.shevchenko@...el.com, heikki.krogerus@...ux.intel.com,
        mika.westerberg@...ux.intel.com, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] mfd: intel-lpss: Do not put device in reset state on
 suspend

On Wed, 12 Oct 2016, Azhar Shaikh wrote:

> Commit 41a3da2b8e163 ("mfd: intel-lpss: Save register context on
> suspend") saved the register context while going to suspend and
> also put the device in reset state.
> 
> Due to the resetting of device, system cannot enter S3/S0ix
> states when no_console_suspend flag is enabled. The system
> and serial console both hang. The resetting of device is not
> needed while going to suspend. Hence remove this code.
> 
> Fixes: 41a3da2b8e163 ("mfd: intel-lpss: Save register context on suspend")
> Signed-off-by: Azhar Shaikh <azhar.shaikh@...el.com>
> ---
>  drivers/mfd/intel-lpss.c | 3 ---
>  1 file changed, 3 deletions(-)

Applied with Acks and sent to Stable.

> diff --git a/drivers/mfd/intel-lpss.c b/drivers/mfd/intel-lpss.c
> index 41b1138..70c646b 100644
> --- a/drivers/mfd/intel-lpss.c
> +++ b/drivers/mfd/intel-lpss.c
> @@ -502,9 +502,6 @@ int intel_lpss_suspend(struct device *dev)
>  	for (i = 0; i < LPSS_PRIV_REG_COUNT; i++)
>  		lpss->priv_ctx[i] = readl(lpss->priv + i * 4);
>  
> -	/* Put the device into reset state */
> -	writel(0, lpss->priv + LPSS_PRIV_RESETS);
> -
>  	return 0;
>  }
>  EXPORT_SYMBOL_GPL(intel_lpss_suspend);

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