On 12/05, Pierre-Louis Bossart wrote:

Hi, In the modified cht-bsw_rt5645 machine driver for Asus X205TA and T100HA, I disable the audio mclk with a call to clk_disable_unprepare() when I see a SND_SOC_DAPM_EVENT_OFF event in the platform_clock_control hook.

For some reason I seem to get multiple SND_SOC_DAPM_EVENT_OFF events and the clock framework complains with dmesg warnings that the refcount is already zero (which has no functional side effect).

WARNING: CPU: 0 PID: 2002 at drivers/clk/clk.c:476 clk_unprepare+0x1a/0x21

WARNING: CPU: 2 PID: 2095 at drivers/clk/clk.c:594 clk_core_disable_lock+0x12/0x1b

I could fix this in three different ways:

• remove multiple SND_SOC_DAPM_EVENT_OFF events (not sure what the

root cause is, maybe issues with jack detection?)

It would be good to know what the root cause is here before thinking about doing anything else.

• call a clk_is_enabled() or clk_refcount() function before calling

clk_disable_unprepare() (but they don't seem to exist in include/linux/clk.h)

• count the references myself (which does exactly the same as what

the clk framework already does so it's not terribly elegant)

Both of these sound like hacks around the problem of unbalanced off event calls.