On Tue, Aug 04, 2020 at 12:22:53PM +0800, Shengjiu Wang wrote:
Btw, do we need similar change for TRIGGER_STOP?
This is a good question. It is better to do change for STOP, but I am afraid that there is no much test to guarantee the result.
Maybe we can do this change for STOP.
The idea looks good to me...(check inline comments)
diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c index 1c0e06bb3783..6e4be398eaee 100644 --- a/sound/soc/fsl/fsl_sai.c +++ b/sound/soc/fsl/fsl_sai.c @@ -517,6 +517,37 @@ static int fsl_sai_hw_free(struct snd_pcm_substream *substream, return 0; }
+static void fsl_sai_config_disable(struct fsl_sai *sai, bool tx) +{
unsigned int ofs = sai->soc_data->reg_offset;u32 xcsr, count = 100;regmap_update_bits(sai->regmap, FSL_SAI_xCSR(tx, ofs),FSL_SAI_CSR_TERE, 0);/* TERE will remain set till the end of current frame */do {udelay(10);regmap_read(sai->regmap, FSL_SAI_xCSR(tx, ofs), &xcsr);} while (--count && xcsr & FSL_SAI_CSR_TERE);regmap_update_bits(sai->regmap, FSL_SAI_xCSR(tx, ofs),FSL_SAI_CSR_FR, FSL_SAI_CSR_FR);/** For sai master mode, after several open/close sai,* there will be no frame clock, and can't recover* anymore. Add software reset to fix this issue.* This is a hardware bug, and will be fix in the* next sai version.*/if (!sai->is_slave_mode) {/* Software Reset for both Tx and Rx */
Remove "for both Tx and Rx"
/* Check if the opposite FRDE is also disabled */ regmap_read(sai->regmap, FSL_SAI_xCSR(!tx, ofs), &xcsr);
if (sai->synchronous[tx] && !sai->synchronous[!tx] && !(xcsr & FSL_SAI_CSR_FRDE))fsl_sai_config_disable(sai, !tx);
if (sai->synchronous[tx] || !sai->synchronous[!tx] || !(xcsr & FSL_SAI_CSR_FRDE))fsl_sai_config_disable(sai, tx);
The first "||" should probably be "&&".
The trigger() logic is way more complicated than a simple cleanup in my opinion. Would suggest to split RMR part out of this change.
And for conditions like "sync[tx] && !sync[!tx]", it'd be better to have a helper function to improve readability:
/** * fsl_sai_dir_is_synced - Check if stream is synced by the opposite stream * * SAI supports synchronous mode using bit/frame clocks of either Transmitter's * or Receiver's for both streams. This function is used to check if clocks of * current stream's are synced by the opposite stream. * * @sai: SAI context * @dir: direction of current stream */ static inline bool fsl_sai_dir_is_synced(struct fsl_sai *sai, int dir) { int adir = (dir == TX) ? RX : TX;
/* current dir in async mode while opposite dir in sync mode */ return !sai->synchronous[dir] && sai->synchronous[adir]; }
Then add more comments in trigger:
static ...trigger() { bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK; int adir = tx ? RX : TX; int dir = tx ? TX : RX;
// .... { // ...
/* Check if the opposite FRDE is also disabled */ regmap_read(sai->regmap, FSL_SAI_xCSR(!tx, ofs), &xcsr);
/* * If opposite stream provides clocks for synchronous mode and * it is inactive, disable it before disabling the current one */ if (fsl_sai_dir_is_synced(adir) && !(xcsr & FSL_SAI_CSR_FRDE)) fsl_sai_config_disable(sai, adir);
/* * Disable current stream if either of: * 1. current stream doesn't provide clocks for synchronous mode * 2. current stream provides clocks for synchronous mode but no * more stream is active. */ if (!fsl_sai_dir_is_synced(dir) || !(xcsr & FSL_SAI_CSR_FRDE)) fsl_sai_config_disable(sai, dir);
// ... } // .... }
Note, in fsl_sai_config_disable(sai, dir): bool tx = dir == TX;
Above all, I am just drafting, so please test it thoroughly :)