Re: [PATCH V3] i2c: busses: tegra: Add suspend-resume support

From: Bitan Biswas <bbiswas@nvidia.com>
To: Dmitry Osipenko <digetx@gmail.com>,
	Laxman Dewangan <ldewangan@nvidia.com>,
	Thierry Reding <treding@nvidia.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	<linux-i2c@vger.kernel.org>, <linux-tegra@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>
Cc: Shardar Mohammed <smohammed@nvidia.com>,
	Sowjanya Komatineni <skomatineni@nvidia.com>,
	Mantravadi Karthik <mkarthik@nvidia.com>,
	"Wolfram Sang" <wsa@the-dreams.de>
Subject: Re: [PATCH V3] i2c: busses: tegra: Add suspend-resume support
Date: Thu, 13 Jun 2019 05:00:43 -0700	[thread overview]
Message-ID: <508037a2-52cb-43e8-24a9-1c064972d2d8@nvidia.com> (raw)
In-Reply-To: <21a2b722-cd1d-284f-2a4d-99bb12c98afd@gmail.com>

On 6/6/19 11:27 PM, Dmitry Osipenko wrote:
> 07.06.2019 8:37, Bitan Biswas пишет:
>> Post suspend I2C registers have power on reset values. Before any
>> transfer initialize I2C registers to prevent I2C transfer timeout
>> and implement suspend and resume callbacks needed. Fix below errors
>> post suspend:
>>
>> 1) Tegra I2C transfer timeout during jetson tx2 resume:
>>
>> [   27.520613] pca953x 1-0074: calling pca953x_resume+0x0/0x1b0 @ 2939, parent: i2c-1
>> [   27.633623] tegra-i2c 3160000.i2c: i2c transfer timed out
>> [   27.639162] pca953x 1-0074: Unable to sync registers 0x3-0x5. -110
>> [   27.645336] pca953x 1-0074: Failed to sync GPIO dir registers: -110
>> [   27.651596] PM: dpm_run_callback(): pca953x_resume+0x0/0x1b0 returns -110
>> [   27.658375] pca953x 1-0074: pca953x_resume+0x0/0x1b0 returned -110 after 127152 usecs
>> [   27.666194] PM: Device 1-0074 failed to resume: error -110
>>
>> 2) Tegra I2C transfer timeout error on jetson Xavier post resume.
>>
>> Remove i2c bus lock-unlock calls in resume callback as i2c_mark_adapter_*
>> (suspended-resumed) help ensure i2c core calls from client are not
>> executed before i2c-tegra resume.
>>
>> Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
>> ---
>>   drivers/i2c/busses/i2c-tegra.c | 24 ++++++++++++++++++++++++
>>   1 file changed, 24 insertions(+)
>>
>> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
>> index ebaa78d..1dbba39 100644
>> --- a/drivers/i2c/busses/i2c-tegra.c
>> +++ b/drivers/i2c/busses/i2c-tegra.c
>> @@ -1687,7 +1687,31 @@ static int tegra_i2c_remove(struct platform_device *pdev)
>>   }
>>   
>>   #ifdef CONFIG_PM_SLEEP
>> +static int tegra_i2c_suspend(struct device *dev)
>> +{
>> +	struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
>> +
>> +	i2c_mark_adapter_suspended(&i2c_dev->adapter);
>> +
>> +	return 0;
>> +}
>> +
>> +static int tegra_i2c_resume(struct device *dev)
>> +{
>> +	struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
>> +	int err;
>> +
>> +	err = tegra_i2c_init(i2c_dev, false);
>> +	if (err)
>> +		return err;
>> +
>> +	i2c_mark_adapter_resumed(&i2c_dev->adapter);
>> +
>> +	return 0;
>> +}
>> +
>>   static const struct dev_pm_ops tegra_i2c_pm = {
>> +	SET_SYSTEM_SLEEP_PM_OPS(tegra_i2c_suspend, tegra_i2c_resume)
>>   	SET_RUNTIME_PM_OPS(tegra_i2c_runtime_suspend, tegra_i2c_runtime_resume,
>>   			   NULL)
>>   };
>>
> 
> Thanks!
> 
> Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
> 

Please get back if there is/are any further review comment(s) for below 
patch.

http://patchwork.ozlabs.org/patch/1111570/

-Thanks,
  Bitan