linux-kernel - Re: [PATCH v2 2/3] i2c: davinci: Add PM Runtime Support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <bd204f3b-8bfd-9015-18cc-dd915c88b812@ti.com>
Date:   Tue, 22 Aug 2017 10:52:39 +0530
From:   Sekhar Nori <nsekhar@...com>
To:     Franklin S Cooper Jr <fcooper@...com>, <wsa@...-dreams.de>,
        <robh+dt@...nel.org>, <linux@...linux.org.uk>,
        <linux-i2c@...r.kernel.org>, <devicetree@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>, <grygorii.strashko@...com>,
        <vigneshr@...com>
Subject: Re: [PATCH v2 2/3] i2c: davinci: Add PM Runtime Support

On Tuesday 22 August 2017 06:47 AM, Franklin S Cooper Jr wrote:
> 
> 
> On 08/21/2017 04:05 AM, Sekhar Nori wrote:
>> On Thursday 17 August 2017 03:47 AM, Franklin S Cooper Jr wrote:
>>
>>> @@ -802,7 +821,6 @@ static int davinci_i2c_probe(struct platform_device *pdev)
>>>  	dev->clk = devm_clk_get(&pdev->dev, NULL);
>>>  	if (IS_ERR(dev->clk))
>>>  		return PTR_ERR(dev->clk);
>>> -	clk_prepare_enable(dev->clk);
>>>  
>>>  	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>>  	dev->base = devm_ioremap_resource(&pdev->dev, mem);
>>> @@ -811,6 +829,18 @@ static int davinci_i2c_probe(struct platform_device *pdev)
>>>  		goto err_unuse_clocks;
>>
>> This goto is wrong now. There is no need to unwind the pm_runtime setup
>> on a devm_ioremap_resource() failure. You can just return error here.
> 
> Ok
>>
>>>  	}
>>>  
>>> +	pm_runtime_set_autosuspend_delay(dev->dev,
>>> +					 DAVINCI_I2C_PM_TIMEOUT);
>>> +	pm_runtime_use_autosuspend(dev->dev);
>>> +
>>> +	pm_runtime_enable(dev->dev);
>>> +
>>> +	r = pm_runtime_get_sync(dev->dev);
>>> +	if (r < 0) {
>>> +		dev_err(dev->dev, "failed to runtime_get device: %d\n", r);
>>> +		goto err_unuse_clocks;
>>> +	}
>>> +
>>>  	i2c_davinci_init(dev);
>>>  
>>>  	r = devm_request_irq(&pdev->dev, dev->irq, i2c_davinci_isr, 0,
>>> @@ -849,10 +879,16 @@ static int davinci_i2c_probe(struct platform_device *pdev)
>>>  	if (r)
>>>  		goto err_unuse_clocks;
>>>  
>>> +	pm_runtime_mark_last_busy(dev->dev);
>>> +	pm_runtime_put_autosuspend(dev->dev);
>>> +
>>>  	return 0;
>>>  
>>>  err_unuse_clocks:
>>> -	clk_disable_unprepare(dev->clk);
>>> +	pm_runtime_dont_use_autosuspend(dev->dev);
>>> +	pm_runtime_put_sync(dev->dev);
>>> +	pm_runtime_disable(dev->dev);
>>> +
>>>  	dev->clk = NULL;
>>
>> This null setting of clk seems quite bogus and can be cleaned-up.
> 
> Do you mean that I should just remove this line?

Yes, and I noticed a similar line in at least one more place that can be
removed as well.

Thanks,
Sekhar