On Mon, Apr 3, 2017 at 1:32 PM, Caleb Crome caleb@crome.org wrote:
On Sat, Apr 1, 2017 at 7:48 AM, Fabio Estevam festevam@gmail.com wrote:
From: Fabio Estevam fabio.estevam@nxp.com
Commit f8fdf5375e2005f2 ("ASoC: fsl-ssi: add SSIEN errata work around") implemented the workaround for the following erratum found on i.MX35 errata document:
ENGcm06222: SSI:Transmission does not take place in bit length early frame sync configuration
and also for ENGcm06222 from the same document.
However it has been only applied for AC97 mode. Apply it to I2S mode as well so that it can fix audio channel swap during playback start.
The channel swap can be noticed in about 10% of the times an audio track starts.
With the recommended workaround in place no more channel swap happened after running audio start/stop sequence in more than 2000 times.
Tested on a mx6dl-wandboard.
Signed-off-by: Fabio Estevam fabio.estevam@nxp.com
Changes since v1:
- Do not impact 61fcf10a0ee44763e0 ("ASoC: fsl_ssi: Fix channel slipping in
Playback at startup")
sound/soc/fsl/fsl_ssi.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c index 17f92b8..549b2a5 100644 --- a/sound/soc/fsl/fsl_ssi.c +++ b/sound/soc/fsl/fsl_ssi.c @@ -575,7 +575,9 @@ static void fsl_ssi_config(struct fsl_ssi_private *ssi_private, bool enable, "Timeout waiting TX FIFO filling\n"); } }
regmap_update_bits(regs, CCSR_SSI_SCR, vals->scr, vals->scr);
regmap_update_bits(regs, CCSR_SSI_SCR,CCSR_SSI_SCR_SSIEN | CCSR_SSI_SCR_TE | CCSR_SSI_SCR_RE,CCSR_SSI_SCR_SSIEN | CCSR_SSI_SCR_TE | CCSR_SSI_SCR_RE); }}
-- 2.7.4
This patch definitely breaks the i.mx6 channel alignment. In fact it breaks it so that the channels are never aligned properly.
My test setup is as follows:
- Get vanilla kernel, tag v4.11-rc5
- apply a couple patches to allow AUD4 on the wandboard external
connectors (and disable internal audio)
FYI, for anybody that wants to test for themselves, I just posted the patches for the wandboard here.
https://github.com/ccrome/linux-caleb-dev/wiki
Now that the SSI patches are in the mainline kernel, these 2 simple patches should make testing the i.mx6 ssi pretty much trivial for anybody.
-Caleb