availability of interrupts during bootup process

[Warner Losh]

On Sep 4, 2012, at 10:05 AM, John Baldwin wrote:

> On Sunday, September 02, 2012 5:31:21 pm Aleksander Dutkowski wrote:
>> hello!
>> 
>> I have PMIC (TWL4030) module connected to the SoC (ARM/OMAP3) via i2c 
> (iicbus).
>> Current solution is that i2c_attach calls bus_generic_attach(dev);
>> which calls my pmic probe/attach functions, but main configuration of
>> PMIC in done after drivers setup by config_intrhook.
>> But I need it to be configured during device attaching, because usb
>> ehci driver depends on it.
>> Is it possbile? I've tried it but it hangs on waiting for i2c
>> interrupt, but someone told me, that interrupts are available during
>> bootup for some time.
> 
> No, interrupts do not work during bootup.  If you can poll your hardware
> you could use polling until interrupts are enabled (using 'if (cold)' to
> check for the boot time before interrupts are enabled).

Are interrupts off, or ithreads not scheduled?  I thought I had some stuff working that needed interrupts, but didn't need scheduling..  Am I nuts?

Warner