Re: [PATCH 09/46] dmaengine: cppi41: use dmaenginem_async_device_register to simplify the code

[Huang Shijie <sjhuang@iluvatar.ai>]

在 2018年08月03日 15:55, Peter Ujfalusi 写道:
>
> On 2018-08-03 10:19, Huang Shijie wrote:
>> Use dmaenginem_async_device_register to simplify the code:
>>     remove dma_async_device_unregister
>>
>> Signed-off-by: Huang Shijie <sjhuang@iluvatar.ai>
>> ---
>>   drivers/dma/ti/cppi41.c | 7 ++-----
>>   1 file changed, 2 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/dma/ti/cppi41.c b/drivers/dma/ti/cppi41.c
>> index 1497da367710..d2998a19ed2e 100644
>> --- a/drivers/dma/ti/cppi41.c
>> +++ b/drivers/dma/ti/cppi41.c
>> @@ -1096,21 +1096,19 @@ static int cppi41_dma_probe(struct platform_device *pdev)
>>   		goto err_chans;
>>   	cdd->irq = irq;
>>   
>> -	ret = dma_async_device_register(&cdd->ddev);
>> +	ret = dmaenginem_async_device_register(&cdd->ddev);
>>   	if (ret)
>>   		goto err_chans;
>>   
>>   	ret = of_dma_controller_register(dev->of_node,
>>   			cppi41_dma_xlate, &cpp41_dma_info);
>>   	if (ret)
>> -		goto err_of;
>> +		goto err_chans;
>>   
>>   	pm_runtime_mark_last_busy(dev);
>>   	pm_runtime_put_autosuspend(dev);
>>   
>>   	return 0;
>> -err_of:
>> -	dma_async_device_unregister(&cdd->ddev);
>>   err_chans:
>>   	deinit_cppi41(dev, cdd);
>>   err_init_cppi:
>> @@ -1132,7 +1130,6 @@ static int cppi41_dma_remove(struct platform_device *pdev)
>>   		dev_err(&pdev->dev, "%s could not pm_runtime_get: %i\n",
>>   			__func__, error);
>>   	of_dma_controller_free(pdev->dev.of_node);
>> -	dma_async_device_unregister(&cdd->ddev);
> If I read the code right then this is not safe.
> We would have deinitalized cppi41 driver which is not functional, but we
> will still have the dma device registered and if a channel is requested
> we will have kernel crash.
>
> It falls in the same case as omap-dma, edma.
Thanks for pointing this, we can drop the patches for omap-dma, edma.

Huang Shijie