Re: [PATCH v11 10/27] iommu/exynos: use managed device helper functions

[Tomasz Figa <t.figa-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>]

On 18.03.2014 11:38, Cho KyongHo wrote:
> On Fri, 14 Mar 2014 14:28:36 +0100, Tomasz Figa wrote:
>> Hi KyongHo,
>>
>> On 14.03.2014 06:05, Cho KyongHo wrote:
>>> This patch uses managed device helper functions in the probe().
>>>
>>> Signed-off-by: Cho KyongHo <pullip.cho-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
>>> ---
>>>    drivers/iommu/exynos-iommu.c |   64 +++++++++++++++++-------------------------
>>>    1 file changed, 26 insertions(+), 38 deletions(-)
>>>
>>> diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
>>> index 36e6b73..33b424d 100644
>>> --- a/drivers/iommu/exynos-iommu.c
>>> +++ b/drivers/iommu/exynos-iommu.c
>>> @@ -499,51 +499,48 @@ void exynos_sysmmu_tlb_invalidate(struct device *dev)
>>>
>>>    static int exynos_sysmmu_probe(struct platform_device *pdev)
>>>    {
>>> -	int ret;
>>> +	int irq, ret;
>>>    	struct device *dev = &pdev->dev;
>>>    	struct sysmmu_drvdata *data;
>>>    	struct resource *res;
>>>
>>> -	data = kzalloc(sizeof(*data), GFP_KERNEL);
>>> -	if (!data) {
>>> -		dev_dbg(dev, "Not enough memory\n");
>>> -		ret = -ENOMEM;
>>> -		goto err_alloc;
>>> -	}
>>> +	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
>>> +	if (!data)
>>> +		return -ENOMEM;
>>>
>>>    	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>>    	if (!res) {
>>> -		dev_dbg(dev, "Unable to find IOMEM region\n");
>>> -		ret = -ENOENT;
>>> -		goto err_init;
>>> +		dev_err(dev, "Unable to find IOMEM region\n");
>>> +		return -ENOENT;
>>>    	}
>>
>> No need to check for error and print message, because
>> devm_ioremap_resource() already checks the passed resource and handles
>> error cases.
>>
>
> Yes but devm_ioremap_resource() just tells that the given 'res' is not
> correct. I think the message in the driver is more informative.

The common practice used in Linux kernel is to not duplicate such 
messages. It is obvious that devm_ioremap_resource() printing such 
message is related to an IOMEM resource anyway, as you can't used it 
with other types of resources.

Best regards,
Tomasz