From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dmitry Osipenko <digetx@gmail.com>
Subject: Re: [PATCH V14 3/5] i2c: tegra: Add DMA support
Date: Thu, 7 Feb 2019 18:56:12 +0300
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To: Sowjanya Komatineni <skomatineni@nvidia.com>, "thierry.reding@gmail.com" <thierry.reding@gmail.com>, Jonathan Hunter <jonathanh@nvidia.com>, Mantravadi Karthik <mkarthik@nvidia.com>, Shardar Mohammed <smohammed@nvidia.com>, Timo Alho <talho@nvidia.com>
Cc: "linux-tegra@vger.kernel.org" <linux-tegra@vger.kernel.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "linux-i2c@vger.kernel.org" <linux-i2c@vger.kernel.org>
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07.02.2019 18:17, Sowjanya Komatineni пишет:
>>>
>>>> @@ -1124,6 +1453,10 @@ static int tegra_i2c_probe(struct platform_device *pdev)
>>>>  		}
>>>>  	}
>>>>  
>>>> +	ret = tegra_i2c_init_dma(i2c_dev);
>>>> +	if (ret < 0)
>>>> +		goto disable_div_clk;
>>>> +
>>>>  	ret = tegra_i2c_init(i2c_dev);
>>>>  	if (ret) {
>>>>  		dev_err(&pdev->dev, "Failed to initialize i2c controller\n");
>>>
>>>
>>> Missing DMA resourcing release on probe failure.
>>
> If probe fails due to other reasons, then I2C interface will not be available and boot will not even happen.
> Do we need DMA resourcing release?
> Probe can fail due to timeout or from pm_runtime.. and if i2c fails lots of things don’t happen properly and doesn’t boot.
> 
> Will add but want to check..
> 

1) There is no guarantee that other error cases won't return -EPROBE_DEFER.

2) I2C driver could be compiled as a module.

3) It is simply a bad programming practice to leak resources.