--- Begin Message ---
- To: "shengjiu.wang@xxxxxxxxx" <shengjiu.wang@xxxxxxxxx>
- Subject: Re: [PATCH] ASoC: fsl_sai: Use physical format width
- From: Emil Abildgaard Svendsen <EMAS@xxxxxxxxxxxxxxx>
- Date: Fri, 31 Mar 2023 14:26:33 +0000
- Cc: Emil Abildgaard Svendsen <EMAS@xxxxxxxxxxxxxxx>, "Xiubo.Lee@xxxxxxxxx" <Xiubo.Lee@xxxxxxxxx>, "alsa-devel@xxxxxxxxxxxxxxxx" <alsa-devel@xxxxxxxxxxxxxxxx>, "broonie@xxxxxxxxxx" <broonie@xxxxxxxxxx>, "festevam@xxxxxxxxx" <festevam@xxxxxxxxx>, "lgirdwood@xxxxxxxxx" <lgirdwood@xxxxxxxxx>, "linuxppc-dev@xxxxxxxxxxxxxxxx" <linuxppc-dev@xxxxxxxxxxxxxxxx>, "nicoleotsuka@xxxxxxxxx" <nicoleotsuka@xxxxxxxxx>, "tiwai@xxxxxxxx" <tiwai@xxxxxxxx>
- In-reply-to: <CAA+D8AOMTQ00Ah21w54DVXin3KcYkVxaGVd64Z_pSzv+Ooj9vw@mail.gmail.com>
- References: <CAA+D8AOMTQ00Ah21w54DVXin3KcYkVxaGVd64Z_pSzv+Ooj9vw@mail.gmail.com>
On 3/31/23 04:55, Shengjiu Wang wrote: > On Thu, Mar 30, 2023 at 4:30 PM Emil Abildgaard Svendsen < > EMAS@xxxxxxxxxxxxxxx> wrote: > >> Slot width should follow the physical width of the format instead of the >> data width. >> >> This is needed for formats like SNDRV_PCM_FMTBIT_S24_LE where physical >> width is 32 and data width is 24. By using the physical width, data >> won't get misaligned. > > > There are different requirements for this slot width. Some need physical > width, > Some need format width. We need to be careful about change here. I might be wrong but shouldn't physical width always correspond to what can be physically measured. If you need the slot width, the same as format width you use a format with matching widths like SNDRV_PCM_FORMAT_S24_3LE? > > Actually there is .set_tdm_slot API for slot specific setting, please use > this API. But if you're using the generic sound cards. You need to add it to the DTS. Thus, if you want a static TDM slot width, all is fine. But if you want to change slot width runtime then it isn't enough. Unless I missed something. Kind regards, Emil Svendsen > > best regards > wang shengjiu > >> >> Signed-off-by: Emil Svendsen <emas@xxxxxxxxxxxxxxx> >> --- >> sound/soc/fsl/fsl_sai.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c >> index 939c6bdd22c4..213e2d462076 100644 >> --- a/sound/soc/fsl/fsl_sai.c >> +++ b/sound/soc/fsl/fsl_sai.c >> @@ -519,13 +519,13 @@ static int fsl_sai_hw_params(struct >> snd_pcm_substream *substream, >> unsigned int channels = params_channels(params); >> struct snd_dmaengine_dai_dma_data *dma_params; >> struct fsl_sai_dl_cfg *dl_cfg = sai->dl_cfg; >> + u32 slot_width = params_physical_width(params); >> u32 word_width = params_width(params); >> int trce_mask = 0, dl_cfg_idx = 0; >> int dl_cfg_cnt = sai->dl_cfg_cnt; >> u32 dl_type = FSL_SAI_DL_I2S; >> u32 val_cr4 = 0, val_cr5 = 0; >> u32 slots = (channels == 1) ? 2 : channels; >> - u32 slot_width = word_width; >> int adir = tx ? RX : TX; >> u32 pins, bclk; >> u32 watermark; >> -- >> 2.34.1 >> >
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