linux-kernel - Re: [PATCH] mmc: sdhci-pxav3: don't disable clocks when we might get an interrupt

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Date:   Tue, 15 May 2018 09:37:26 +0300
From:   Adrian Hunter <adrian.hunter@...el.com>
To:     Tom Hebb <tommyhebb@...il.com>, linux-kernel@...r.kernel.org
Cc:     Ulf Hansson <ulf.hansson@...aro.org>,
        "open list:SECURE DIGITAL HOST CONTROLLER INTERFACE (SDHCI...)" 
        <linux-mmc@...r.kernel.org>,
        Benoît Thébaudeau 
        <benoit.thebaudeau.dev@...il.com>,
        Michael Trimarchi <michael@...rulasolutions.com>,
        Andrew Gabbasov <andrew_gabbasov@...tor.com>
Subject: Re: [PATCH] mmc: sdhci-pxav3: don't disable clocks when we might get
 an interrupt

On 15/05/18 09:18, Tom Hebb wrote:
> Hi,
> 
> On 05/15/2018 01:59 AM, Adrian Hunter wrote:
>> On 15/05/18 00:56, Thomas Hebb wrote:
>>> Currently, runtime_suspend() unconditionally disables the clock gates
>>> for the controller, which means that it's unable to receive interrupts
>>> generated by connected SDIO cards.
>>
>> We currently get / put runtime pm with enable / disable of the SDIO IRQ
>> (refer sdhci_enable_sdio_irq()) so are you sure this is needed?
> 
> You're correct; this patch is unnecessary. I wrote it before
> 923713b35745 ("mmc: sdhci: Disable runtime pm when the sdio_irq is
> enabled"), and it was needed then. Sorry for the noise.
> 
> FYI, sdhci-esdhc-imx still checks the IRQ in its suspend/resume
> functions. That's one of the things that misled me to think this patch
> was still relevant.

+ a few people that have worked on sdhci-esdhc-imx

> 
>>>
>>> Signed-off-by: Thomas Hebb <tommyhebb@...il.com>
>>> ---
>>>  drivers/mmc/host/sdhci-pxav3.c | 16 ++++++++++------
>>>  1 file changed, 10 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/drivers/mmc/host/sdhci-pxav3.c b/drivers/mmc/host/sdhci-pxav3.c
>>> index a34434166ca7..59760f3cc1d7 100644
>>> --- a/drivers/mmc/host/sdhci-pxav3.c
>>> +++ b/drivers/mmc/host/sdhci-pxav3.c
>>> @@ -562,9 +562,11 @@ static int sdhci_pxav3_runtime_suspend(struct device *dev)
>>>  	if (host->tuning_mode != SDHCI_TUNING_MODE_3)
>>>  		mmc_retune_needed(host->mmc);
>>>  
>>> -	clk_disable_unprepare(pxa->clk_io);
>>> -	if (!IS_ERR(pxa->clk_core))
>>> -		clk_disable_unprepare(pxa->clk_core);
>>> +	if (!sdhci_sdio_irq_enabled(host)) {
>>> +		clk_disable_unprepare(pxa->clk_io);
>>> +		if (!IS_ERR(pxa->clk_core))
>>> +			clk_disable_unprepare(pxa->clk_core);
>>> +	}
>>>  
>>>  	return 0;
>>>  }
>>> @@ -575,9 +577,11 @@ static int sdhci_pxav3_runtime_resume(struct device *dev)
>>>  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>>>  	struct sdhci_pxa *pxa = sdhci_pltfm_priv(pltfm_host);
>>>  
>>> -	clk_prepare_enable(pxa->clk_io);
>>> -	if (!IS_ERR(pxa->clk_core))
>>> -		clk_prepare_enable(pxa->clk_core);
>>> +	if (!sdhci_sdio_irq_enabled(host)) {
>>> +		clk_prepare_enable(pxa->clk_io);
>>> +		if (!IS_ERR(pxa->clk_core))
>>> +			clk_prepare_enable(pxa->clk_core);
>>> +	}
>>>  
>>>  	return sdhci_runtime_resume_host(host);
>>>  }
>>>
>>
>