Re: [alsa-devel] [PATCH] ALSA: ASoC: cs4720: use snd_soc_cache_sync()

Daniel Mack wrote:

The code is so simple that I'm starting to suspect i2c_smbus_write_byte_data() is doing something very wrong, but I can't trace it without a hardware I2C analyzer right now. The i2c-regmap low-level implementation uses different access functions under the hood, so maybe that's a regression.

What platform are you testing this on? I never really understood the i2c vs. smbus thing (I can never tell which function an i2c device really needs), so I only know that the i2c code works on my PowerPC board.

Also keep in mind that a patch that affects i2c_smbus_write_byte_data() on PowerPC was recently posted, but not approved yet. Check the thread, "i2c/busses: (mpc) Add support for SMBUS_READ_BLOCK_DATA".