Re: kernel panic in spi_complete() on spitz (PXA270)

[Stanislav Brabec <utx@penguin.cz>]

Igor Grinberg wrote:
> On 06/30/11 17:45, Stanislav Brabec wrote:
> I want to
> > add .needs_regulator bool to ads7846.c and send the patch again to the
> > list.
> 
> Please, don't...
> I thought we've finished discussing the regulator issue...

The discussion ended without a fix (at least for spitz). I seen two
proposals:
- As ADS7846 hardware does not require dedicated regulator, don't
  require it in driver and fail only on platforms that have a dedicated
  regulator.
- Use dummy regulators for all platforms without dedicated ADS7846
  regulator.

>1) add regulator definition for ads7846 into the board file
There is no dedicated regulator on spitz, ADS7846 uses common always-on
power supply.

>2) enable the CONFIG_REGULATOR_DUMMY in your kernel configuration
>3) use regulator_use_dummy_regulator() call in the board file.

OK, I will do 2 or 3. In the new kernel spitz has a regulator, but it is
not related to ADS7846. And it is actually broken:

I2C: i2c-0: PXA I2C adapter
Resetting I2C Controller Unit
 (null): i2c_pxa_abort: called in slave mode
i2c i2c-1: adapter [pxa_i2c-i2c.1] registered
i2c 1-000c: uevent
isl6271a 1-000c: probe
i2c i2c-1: master_xfer[0] R, addr=0x0c, len=1
i2c i2c-1: setting to bus master
i2c i2c-1: state:i2c_pxa_handler:981: ISR=00000442, ICR=000007e0, IBMR=03
i2c i2c-1: state:i2c_pxa_irq_txempty:932: ISR=00000002, ICR=000007e0, IBMR=03
i2c i2c-1: Retrying transmission
i2c i2c-1: setting to bus master
i2c i2c-1: state:i2c_pxa_handler:981: ISR=00000045, ICR=000007e1, IBMR=00
i2c i2c-1: state:i2c_pxa_irq_txempty:932: ISR=00000005, ICR=000017ee, IBMR=00
i2c i2c-1: state:i2c_pxa_handler:981: ISR=00000087, ICR=000017e6, IBMR=00
print_constraints: vcc_core range: 850 <--> 1600 mV at 1350 mV 
print_constraints: vcc_core range: 1100 mV 
isl6271a 1-000c: Failed to set supply vcc_core
isl6271a 1-000c: failed to register isl6271a
isl6271a: probe of 1-000c failed with error -16
i2c i2c-1: client [isl6271a] registered with bus id 1-000c
I2C: i2c-1: PXA I2C adapter
...
cpufreq: Didn't find vcc_core regulator

-- 
Stanislav Brabec
http://www.penguin.cz/~utx