Re: [PATCH -next v2 2/4] soc: ti: knav_dma: Use dev_err_probe() to simplfy code

[Jinjie Ruan <ruanjinjie@huawei.com>]

On 2024/8/30 18:31, Nishanth Menon wrote:
> On 14:32-20240830, Jinjie Ruan wrote:
>> Use the dev_err_probe() helper to simplify error handling
>> during probe.
>>
>> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
>> ---
>> v2:
>> - Split into 2 patches.
>> ---
>>  drivers/soc/ti/knav_dma.c | 12 ++++--------
>>  1 file changed, 4 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/soc/ti/knav_dma.c b/drivers/soc/ti/knav_dma.c
>> index 15e41d3a5e22..eeec422a46f0 100644
>> --- a/drivers/soc/ti/knav_dma.c
>> +++ b/drivers/soc/ti/knav_dma.c
>> @@ -708,17 +708,13 @@ static int knav_dma_probe(struct platform_device *pdev)
>>  	struct device_node *node = pdev->dev.of_node;
>>  	int ret = 0;
>>  
>> -	if (!node) {
>> -		dev_err(&pdev->dev, "could not find device info\n");
>> -		return -EINVAL;
>> -	}
>> +	if (!node)
>> +		return dev_err_probe(&pdev->dev, -EINVAL, "could not find device info\n");
>>  
>>  	kdev = devm_kzalloc(dev,
>>  			sizeof(struct knav_dma_pool_device), GFP_KERNEL);
>> -	if (!kdev) {
>> -		dev_err(dev, "could not allocate driver mem\n");
>> -		return -ENOMEM;
>> -	}
>> +	if (!kdev)
>> +		return dev_err_probe(dev, -ENOMEM, "could not allocate driver mem\n");
> 
> These make no sense to me :( -> just using dev_err_probe when there is
> no chance of -EPROBE_DEFER ?

I noticed a change in dev_err_probe() this year, which is described in
this patch:

For an out-of-memory error there should be no additional output. Adapt
dev_err_probe() to not emit the error message when err is -ENOMEM.
This simplifies handling errors that might among others be -ENOMEM.


And the comment of dev_err_probe() said below:

* Using this helper in your probe function is totally fine even if @err
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
is
~~
 * known to never be -EPROBE_DEFER.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

https://lore.kernel.org/all/3d1e308d45cddf67749522ca42d83f5b4f0b9634.1718311756.git.u.kleine-koenig@baylibre.com/
> 
>>  
>>  	kdev->dev = dev;
>>  	INIT_LIST_HEAD(&kdev->list);
>> -- 
>> 2.34.1
>>
>