On Mon, Nov 20, 2017 at 11:13:45PM +0100, Maciej S. Szmigiero wrote:
In AC'97 mode we configure and start SSI RX / TX on probe path via a call to _fsl_ssi_set_dai_fmt() function. We don't need to call this function again later and in fact don't want to do it since this function temporarily sets STCR, SRCR and SCR to some intermediate values.
We need to make sure, however, that only proper channel slots are enabled at playback start time since some AC'97 CODECs (like VT1613) were observed requesting via SLOTREQ (and so enabling at SSI) spurious ones just after an AC'97 link is started but before the CODEC is configured by its driver.
I don't really understand this part. Why do we need to *make sure* and set SACCDIS and SACCEN again since they're initialized already?
Could you please elaborate a bit more?
Theoretically, this should be necessary only for the very first playback but let's play safe here and make sure that no extra slots are enabled every time a playback is started.
Signed-off-by: Maciej S. Szmigiero mail@maciej.szmigiero.name
sound/soc/fsl/fsl_ssi.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-)
diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c index 48bb850a34d9..dad80b4b0cfc 100644 --- a/sound/soc/fsl/fsl_ssi.c +++ b/sound/soc/fsl/fsl_ssi.c @@ -630,12 +630,6 @@ static void fsl_ssi_setup_ac97(struct fsl_ssi_private *ssi_private) regmap_write(regs, CCSR_SSI_SACNT, CCSR_SSI_SACNT_AC97EN | CCSR_SSI_SACNT_FV);
- /* no SACC{ST,EN,DIS} regs on imx21-class SSI */
- if (!ssi_private->soc->imx21regs) {
regmap_write(regs, CCSR_SSI_SACCDIS, 0xff);regmap_write(regs, CCSR_SSI_SACCEN, 0x300);- }
@@ -1149,9 +1146,16 @@ static int fsl_ssi_trigger(struct snd_pcm_substream *substream, int cmd, case SNDRV_PCM_TRIGGER_START: case SNDRV_PCM_TRIGGER_RESUME: case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {/* no SACC{ST,EN,DIS} regs on imx21-class SSI */if (fsl_ssi_is_ac97(ssi_private) &&!ssi_private->soc->imx21regs) {regmap_write(regs, CCSR_SSI_SACCDIS, 0xff);regmap_write(regs, CCSR_SSI_SACCEN, 0x300);}
And second, why could we ignore them for STREAM_CAPTURE here?
Well, at least this part could be moved into fsl_ssi_tx_config() since we have an abstraction layer of register configurations.
Thanks Nic
fsl_ssi_tx_config(ssi_private, true);
else
} else fsl_ssi_rx_config(ssi_private, true);
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