Re: [alsa-devel] [PATCH] ASoC: dmaengine: Make the pcm->name equal to pcm->id if the name is not set

From: Peter Ujfalusi <peter.ujfalusi@ti.com>
To: Takashi Iwai <tiwai@suse.de>
Cc: alsa-devel@alsa-project.org, broonie@kernel.org,
	lgirdwood@gmail.com, arthur.she@linaro.org
Subject: Re: [alsa-devel] [PATCH] ASoC: dmaengine: Make the pcm->name equal to pcm->id if the name is not set
Date: Wed, 11 Sep 2019 10:22:53 +0300	[thread overview]
Message-ID: <cbc3868a-6f0b-ca4a-671f-fc552181d2f3@ti.com> (raw)
In-Reply-To: <s5hblvs8idi.wl-tiwai@suse.de>

On 10/09/2019 15.07, Takashi Iwai wrote:
> On Fri, 06 Sep 2019 07:55:24 +0200,
> Peter Ujfalusi wrote:
>>
>> Some tools use the snd_pcm_info_get_name() to try to identify PCMs or for
>> other purposes.
>>
>> Currently it is left empty with the dmaengine-pcm, in this case copy the
>> pcm->id string as pcm->name.
>>
>> For example IGT is using this to find the HDMI PCM for testing audio on it.
>>
>> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
>> Reported-by: Arthur She <arthur.she@linaro.org>
>> ---
>> Hi,
>>
>> this was actually reported for 4.14 kernel with omap-pcm (replaced by sdma-pcm
>> in v4.18), since then we only use the generic dmaengine PCM but the same issue
>> applies today.
>>
>> Regards,
>> Peter
>>
>>  sound/soc/soc-generic-dmaengine-pcm.c | 6 ++++++
>>  1 file changed, 6 insertions(+)
>>
>> diff --git a/sound/soc/soc-generic-dmaengine-pcm.c b/sound/soc/soc-generic-dmaengine-pcm.c
>> index 748f5f641002..d93db2c2b527 100644
>> --- a/sound/soc/soc-generic-dmaengine-pcm.c
>> +++ b/sound/soc/soc-generic-dmaengine-pcm.c
>> @@ -306,6 +306,12 @@ static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd)
>>  
>>  		if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i]))
>>  			pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE;
>> +
>> +		if (rtd->pcm->streams[i].pcm->name[0] == '\0') {
>> +			strncpy(rtd->pcm->streams[i].pcm->name,
>> +				rtd->pcm->streams[i].pcm->id,
>> +				sizeof(rtd->pcm->streams[i].pcm->name));
>> +		}
> 
> Any reason to use strncpy() instead of strscpy()?
> After merging Mark's branch, I got a compile warning like:
>   sound/soc/soc-generic-dmaengine-pcm.c:311:4: warning: 'strncpy'
>   accessing 80 bytes at offsets 88 and 24 may overlap up to 0 bytes at
>   offset [9223372036854775807, -9223372036854775808] [-Wrestrict]

fwiw I run it again with sparse and it only reports these:
 CHECK   sound/soc/soc-generic-dmaengine-pcm.c
sound/soc/soc-generic-dmaengine-pcm.c:177:42: warning: restricted snd_pcm_format_t degrades to integer
sound/soc/soc-generic-dmaengine-pcm.c:177:47: warning: restricted snd_pcm_format_t degrades to integer
sound/soc/soc-generic-dmaengine-pcm.c:177:71: warning: restricted snd_pcm_format_t degrades to integer
  CC      sound/soc/soc-generic-dmaengine-pcm.o

gcc 6.4.0...9.2.0
sparse 0.6.0

> 
> 
> Takashi
> 
>>  
>>  	return 0;
>> -- 
>> Peter
>>
>> Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
>> Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
>>
>> _______________________________________________
>> Alsa-devel mailing list
>> Alsa-devel@alsa-project.org
>> https://mailman.alsa-project.org/mailman/listinfo/alsa-devel
>>

- Péter

Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
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