Hi Nicolin,
On Fri, Mar 31, 2017 at 8:53 PM, Nicolin Chen nicoleotsuka@gmail.com wrote:
+#define FSLSSI_SSIEN_WORKAROUND (CCSR_SSI_SCR_SSIEN | CCSR_SSI_SCR_TE | \
CCSR_SSI_SCR_RE)Enable RE??
Yes, same idea as in f8fdf5375e2005f2 ("ASoC: fsl-ssi: add SSIEN errata work around").
The idea here was not to restrict the erratum to AC97 mode only.
enum fsl_ssi_type { FSL_SSI_MCP8610, FSL_SSI_MX21, @@ -559,7 +562,8 @@ static void fsl_ssi_config(struct fsl_ssi_private *ssi_private, bool enable, int i; int max_loop = 100; regmap_update_bits(regs, CCSR_SSI_SCR,
CCSR_SSI_SCR_SSIEN, CCSR_SSI_SCR_SSIEN);
FSLSSI_SSIEN_WORKAROUND,FSLSSI_SSIEN_WORKAROUND); for (i = 0; i < max_loop; i++) { u32 sfcsr; regmap_read(regs, CCSR_SSI_SFCSR, &sfcsr);If this change is made, the whole "if (enable)" part here seems to be meaningless (or even worse) as it aimed to set TE later than SSIEN so as to offset the delay from DMA TX.
Check: https://patchwork.kernel.org/patch/9091051/
If this errata is mandatory, we probably should revert that the commit and find other solution/workaround for Arnaud and Caleb.
Reverting 61fcf10a0ee44763e0 ("ASoC: fsl_ssi: Fix channel slipping in Playback at startup") still causes channel swaps on my tests, so better not to revert it.