arm: pmu: support pmu/perf on OMAP4 - booting problem on pandaboard

Ming Lei tom.leiming at
Sat Apr 2 01:27:05 EDT 2011

Hi Avik,

2011/4/1 Avik Sil <aviksil at>:
> Hi,
> I've applied the patches in
> on top of a linaro kernel which resulted in booting problem on Pandaboard.
> It hangs inside the cti_unlock() while reading the LOCKSTATUS value, which
> happens when omap_init_pmu() is called. Please help me debug the issue.

Please check if  l3 clocks are enabled to drive CTI, such as done in below:

       omap_writel(1, CM_L3INSTR_L3_3_CLKCTRL);
       omap_writel(1, CM_L3INSTR_L3_INSTR_CLKCTRL);
       omap_writel(2, CM_EMU_CLKSTCTRL);
       while ((omap_readl(CM_EMU_CLKSTCTRL) & 0x300) != 0x300);

No such issue on mainline since this clocks are enabled automatically.

Ming Lei

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