Re: [PATCH v2] sound: oss: ad1848: Fix returned errno code in ad1848_init()

[Luis de Bethencourt]

On 25/09/15 07:32, Takashi Iwai wrote:
> On Thu, 24 Sep 2015 21:08:39 +0200,
> Luis de Bethencourt wrote:
>>
>> On 24/09/15 19:56, Takashi Iwai wrote:
>>> On Thu, 24 Sep 2015 19:58:30 +0200,
>>> Luis de Bethencourt wrote:
>>>>
>>>> The driver is using -1 instead of the -ENOMEM defined macro to specify
>>>> that a buffer allocation failed. Since the error number is propagated,
>>>> the caller will get a -EPERM which is the wrong error condition.
>>>
>>> Where is the propagated error number referred?  In other words, do we
>>> have a clear merit of changing this old stuff with rather a risk of
>>> regression?
>>>
>>>
>>> thanks,
>>>
>>> Takashi
>>
>> Hi Takashi,
>>
>> The propagated error number is not referred. The only merit here is to
>> use the appropriate error number and silence the smatch tool.
> 
> In that case, I prefer leaving as is, sorry.  The code is using -1 for
> its purpose, and the error number isn't important there in anyway
> since the driver doesn't abort at all.
> 
> 
> thanks,
> 
> Takashi

Hi Takashi,

I understand. I was on the fence myself about it being worth it or not,
as I mentioned in the review of the first version of the patch.

Thank you for the review,
Luis

> 
>>
>> Thanks for the review,
>> Luis
>>
>>>
>>>> Changed the checks of the return of ad1848_init() to be for >= 0,
>>>> instead of != -1.
>>>>
>>>> Smatch tool warning:
>>>> ad1848_init() warn: returning -1 instead of -ENOMEM is sloppy
>>>>
>>>> Signed-off-by: Luis de Bethencourt <luisbg@xxxxxxxxxxxxxxx>
>>>> ---
>>>>  sound/oss/ad1848.c    | 4 ++--
>>>>  sound/oss/dev_table.c | 2 +-
>>>>  sound/oss/pss.c       | 2 +-
>>>>  3 files changed, 4 insertions(+), 4 deletions(-)
>>>>
>>>> diff --git a/sound/oss/ad1848.c b/sound/oss/ad1848.c
>>>> index 10c8de1..58c6d31 100644
>>>> --- a/sound/oss/ad1848.c
>>>> +++ b/sound/oss/ad1848.c
>>>> @@ -1992,7 +1992,7 @@ int ad1848_init (char *name, struct resource *ports, int irq, int dma_playback,
>>>>  	portc = kmalloc(sizeof(ad1848_port_info), GFP_KERNEL);
>>>>  	if(portc==NULL) {
>>>>  		release_region(devc->base, 4);
>>>> -		return -1;
>>>> +		return -ENOMEM;
>>>>  	}
>>>>  
>>>>  	if ((my_dev = sound_install_audiodrv(AUDIO_DRIVER_VERSION,
>>>> @@ -2007,7 +2007,7 @@ int ad1848_init (char *name, struct resource *ports, int irq, int dma_playback,
>>>>  	{
>>>>  		release_region(devc->base, 4);
>>>>  		kfree(portc);
>>>> -		return -1;
>>>> +		return my_dev;
>>>>  	}
>>>>  	
>>>>  	audio_devs[my_dev]->portc = portc;
>>>> diff --git a/sound/oss/dev_table.c b/sound/oss/dev_table.c
>>>> index 6dad515..abb3db4 100644
>>>> --- a/sound/oss/dev_table.c
>>>> +++ b/sound/oss/dev_table.c
>>>> @@ -148,7 +148,7 @@ EXPORT_SYMBOL(sound_install_mixer);
>>>>  
>>>>  void sound_unload_audiodev(int dev)
>>>>  {
>>>> -	if (dev != -1) {
>>>> +	if (dev >= 0) {
>>>>  		DMAbuf_deinit(dev);
>>>>  		audio_devs[dev] = NULL;
>>>>  		unregister_sound_dsp((dev<<4)+3);
>>>> diff --git a/sound/oss/pss.c b/sound/oss/pss.c
>>>> index 81314f9..e84aafe 100644
>>>> --- a/sound/oss/pss.c
>>>> +++ b/sound/oss/pss.c
>>>> @@ -1091,7 +1091,7 @@ static int __init probe_pss_mss(struct address_info *hw_config)
>>>>  	pss_mixer_reset(devc);
>>>>  	attach_ms_sound(hw_config, ports, THIS_MODULE);	/* Slot 0 */
>>>>  
>>>> -	if (hw_config->slots[0] != -1)
>>>> +	if (hw_config->slots[0] >= 0)
>>>>  	{
>>>>  		/* The MSS driver installed itself */
>>>>  		audio_devs[hw_config->slots[0]]->coproc = &pss_coproc_operations;
>>>> -- 
>>>> 2.5.1
>>>>
>>>>
>>

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