On Mon, 08 Jul 2024 15:34:44 +0200, Jerome Brunet wrote: > > On Mon 01 Jul 2024 at 16:07, Takashi Iwai <tiwai@xxxxxxx> wrote: > > > On Mon, 01 Jul 2024 10:50:02 +0200, > > Amadeusz Sławiński wrote: > >> > >> On 6/28/2024 2:23 PM, Jerome Brunet wrote: > >> > The usual sample rate possible on an SPDIF link are > >> > 32k, 44.1k, 48k, 88.2k, 96k, 172.4k and 192k. > >> > > >> > With higher bandwidth variant, such as eARC, and the introduction of 8 > >> > channels mode, the spdif frame rate may be multiplied by 4. This happens > >> > when the interface use an IEC958_SUBFRAME format. > >> > > >> > The spdif 8 channel mode rate list is: > >> > 128k, 176.4k, 192k, 352.8k, 384k, 705.4k and 768k. > >> > > >> > All are already supported by ASLA expect for the 128kHz one. > >> > Add support for it but do not insert it the SNDRV_PCM_RATE_8000_192000 > >> > macro. Doing so would silently add 128k support to a lot of HW which > >> > probably do not support it. > >> > > >> > Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx> > >> > --- > >> > >> From what I remember the recommendation is to not add new rates, but > >> use SNDRV_PCM_RATE_KNOT for all rates not included already. > > > > In general yes -- unless the new rate is used for significant amount > > of drivers. > > > > So this case is a sort of on a border line; if it's only for ASoC > > SPDIF codec driver, I'd rather implement with an extra rate list > > instead of extending the common bits (that has some potential risks by > > breaking the existing numbers). > > At the moment it would be used by ASoC spdif codec yes (and with Amlogic > eARC support reasonnably soon, hopefully) > > However it is likely to be a common rate of any derivative of an IEC958 > interface, with a sufficiently high bandwidth. I suspect there might be > more of those in the future. Also, it is not an exotic rate for some obscure > codec no one really has. It is part of specified interface that every TV > with HDMI 2 is likely to have nowadays. This is why I thought it made > sense to add it to the usual list. It is the only rate missing, > everything else is already there. > > Changing the spdif codecs with SNDRV_PCM_RATE_KNOT and a custom rate > list is doable I suppose, if the new ID is not OK. > > BTW, I tried not changing the existing numbers and add 128k last but that > broke. I guess something requires the IDs to be ordered. I did not check > this further since updating the IDs worked fine (for me, at least :) ) > > > OTOH, if we can take this for further > > cleanups of the existing requirement of 128khz rate, we can go with > > it. > > > > Apart from the problem reported in sound/usb/caiaq/audio.c, is there > another clean up expected ? The change for caiaq/audio.c is rather a "fix" :) As a cleanup, I meant, whether this extension can be applied to the other existing drivers that already use 128kHz with RATE_KNOT and an extra list. thanks, Takashi
