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 02:18:31 -0400
From:   Tom Hebb <tommyhebb@...il.com>
To:     Adrian Hunter <adrian.hunter@...el.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>
Subject: Re: [PATCH] mmc: sdhci-pxav3: don't disable clocks when we might get
 an interrupt

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.

>>
>> 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);
>>  }
>>
>