From OMAPpedia

HSI

Enable the HSI Kernel trace

1. build the kernel with CONFIG_DYNAMIC_DEBUG=y

2. mount a debug file system on /d/ or /debugfs/ or /debug/

3. type “echo -n 'module omap_hsi +p' > /d/dynamic_debug/control” to enable the trace

4. type “cat /d/dynamic_debug/control | grep hsi” to see only HSI trace

example:

<7>omap_hsi omap_hsi.0: Int Tasklet : clock_enabled=1
<7>omap_hsi omap_hsi.0: CLK: hsi_clocks_enable: do_hsi_tasklet
<7>omap_hsi omap_hsi.0: Clocks already enabled, skipping...
<7>omap_hsi omap_hsi.0: Channels [0,7] : Events 0x00000100
<7>omap_hsi omap_hsi.0: Data Available interrupt for channel 0.
<7>omap_hsi omap_hsi.0: Channels [8,15] : no event, exit.
<7>omap_hsi omap_hsi.0: CLK: hsi_clocks_disable: do_hsi_tasklet
<7>omap_hsi omap_hsi.0: Port 1: WAKE status: acwake_status 1,cur_cawake 1
<7>omap_hsi omap_hsi.0: Port 1 busy
<7>omap_hsi omap_hsi.0: Cannot disable clocks, HSI port busy
<7>omap_hsi omap_hsi.0: Int Tasklet : clock_enabled=1
<7>omap_hsi omap_hsi.0: CLK: hsi_clocks_enable: do_hsi_tasklet

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