Re: [RFC PATCH 2/4] ASoC: soc-generic-dmaengine-pcm: Add custom prepare and submit function
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
- To: Lars-Peter Clausen <lars@xxxxxxxxxx>, "Sit, Michael Wei Hong" <michael.wei.hong.sit@xxxxxxxxx>, "Sia, Jee Heng" <jee.heng.sia@xxxxxxxxx>, "Shevchenko, Andriy" <andriy.shevchenko@xxxxxxxxx>
- Subject: Re: [RFC PATCH 2/4] ASoC: soc-generic-dmaengine-pcm: Add custom prepare and submit function
- From: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
- Date: Mon, 7 Dec 2020 09:36:07 -0600
- Cc: "Rojewski, Cezary" <cezary.rojewski@xxxxxxxxx>, "alsa-devel@xxxxxxxxxxxxxxxx" <alsa-devel@xxxxxxxxxxxxxxxx>, "tiwai@xxxxxxxx" <tiwai@xxxxxxxx>, "liam.r.girdwood@xxxxxxxxxxxxxxx" <liam.r.girdwood@xxxxxxxxxxxxxxx>, "vkoul@xxxxxxxxxx" <vkoul@xxxxxxxxxx>, "broonie@xxxxxxxxxx" <broonie@xxxxxxxxxx>
- In-reply-to: <17462280-244f-0c1e-61f2-6dd197dbcd2d@metafoo.de>
- References: <20201117080354.4309-1-michael.wei.hong.sit@intel.com> <20201117080354.4309-4-michael.wei.hong.sit@intel.com> <20201117155038.GO4077@smile.fi.intel.com> <CO1PR11MB50269CF832CD14BA2D2A883CDAE10@CO1PR11MB5026.namprd11.prod.outlook.com> <20201118145055.GW4077@smile.fi.intel.com> <CO1PR11MB5026A81C4294BEF4EE5EF923DAFB0@CO1PR11MB5026.namprd11.prod.outlook.com> <BYAPR11MB30465A81744EA686D2502DB69DF50@BYAPR11MB3046.namprd11.prod.outlook.com> <e9bae9eb-6b8b-5a8c-eba0-d7f5da955987@metafoo.de> <20201130110915.GI4077@smile.fi.intel.com> <74ed61e1-67d9-d7b7-0619-fbe61ad7a583@metafoo.de> <CO1PR11MB502600945CC303756DBBC30ADAF40@CO1PR11MB5026.namprd11.prod.outlook.com> <BYAPR11MB3046DFC48A045ADA72D0F9369DF00@BYAPR11MB3046.namprd11.prod.outlook.com> <17462280-244f-0c1e-61f2-6dd197dbcd2d@metafoo.de>
- User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0
If you really want to limit your period size you need to install a range
constraint on the SNDRV_PCM_HW_PARAM_PERIOD_SIZE parameter.
But I'd highly recommend against it and just split the transfer into
multiple segments in the DMA driver. Needlessly limiting the period size
will increase the number of interrupts during audio playback/recording
and hurt the power efficiency of your system.
Yes that was also an objection from me, the fix should be in the DMA
level. The 1024 block limitation would mean restricting the period size
to be at most 5.3 or 10.6ms (16 and 32-bit cases). That's way to small.
[Index of Archives]
[ALSA User]
[Linux Audio Users]
[Pulse Audio]
[Kernel Archive]
[Asterisk PBX]
[Photo Sharing]
[Linux Sound]
[Video 4 Linux]
[Gimp]
[Yosemite News]