[PATCH] ALSA: rawmidi: introduce SNDRV_RAWMIDI_IOCTL_USER_PVERSION

[Jaroslav Kysela]

On 20. 09. 21 18:42, David Henningsson wrote:
> 
> On 2021-09-20 10:35, Jaroslav Kysela wrote:
>> The new framing mode causes the user space regression, because
>> the alsa-lib code does not initialize the reserved space in
>> the params structure when the device is opened.
>>
>> This change adds SNDRV_RAWMIDI_IOCTL_USER_PVERSION like we
>> do for the PCM interface for the protocol acknowledgment.
>>
>> Cc: David Henningsson <coding at diwic.se>
>> Cc: <stable at vger.kernel.org>
>> Fixes: 08fdced60ca0 ("ALSA: rawmidi: Add framing mode")
>> BugLink: https://github.com/alsa-project/alsa-lib/issues/178
>> Signed-off-by: Jaroslav Kysela <perex at perex.cz>
>> ---
>>   include/sound/rawmidi.h     | 1 +
>>   include/uapi/sound/asound.h | 1 +
>>   sound/core/rawmidi.c        | 9 +++++++++
>>   3 files changed, 11 insertions(+)
>>
>> diff --git a/include/sound/rawmidi.h b/include/sound/rawmidi.h
>> index 989e1517332d..7a08ed2acd60 100644
>> --- a/include/sound/rawmidi.h
>> +++ b/include/sound/rawmidi.h
>> @@ -98,6 +98,7 @@ struct snd_rawmidi_file {
>>   	struct snd_rawmidi *rmidi;
>>   	struct snd_rawmidi_substream *input;
>>   	struct snd_rawmidi_substream *output;
>> +	unsigned int user_pversion;	/* supported protocol version */
>>   };
>>   
>>   struct snd_rawmidi_str {
>> diff --git a/include/uapi/sound/asound.h b/include/uapi/sound/asound.h
>> index 1d84ec9db93b..f906e50a7919 100644
>> --- a/include/uapi/sound/asound.h
>> +++ b/include/uapi/sound/asound.h
>> @@ -784,6 +784,7 @@ struct snd_rawmidi_status {
>>   
>>   #define SNDRV_RAWMIDI_IOCTL_PVERSION	_IOR('W', 0x00, int)
>>   #define SNDRV_RAWMIDI_IOCTL_INFO	_IOR('W', 0x01, struct snd_rawmidi_info)
>> +#define SNDRV_RAWMIDI_IOCTL_USER_PVERSION _IOW('A', 0x02, int)
> 
> How come it's not 'W' here but 'A' instead?

Good catch. I sent v2 of this patch with this correction. Thank you.

https://lore.kernel.org/alsa-devel/20210920171850.154186-1-perex@perex.cz/

					Jaroslav

> 
> Looks good otherwise, given a quick glance. It'll need a corresponding 
> alsa-lib patch to actually call SNDRV_RAWMIDI_IOCTL_USER_PVERSION.
> 
> Thanks for helping to sort this out.
> 
> // David
> 


-- 
Jaroslav Kysela <perex at perex.cz>
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.