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

From: Igor Grinberg
Date: Thu Jun 30 2011 - 16:50:50 EST




On 06/30/11 21:01, Mark Brown wrote:
> On Thu, Jun 30, 2011 at 08:40:40PM +0300, Igor Grinberg wrote:
>> On 06/30/11 19:13, Stanislav Brabec wrote:
>
>>> 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.
>> The thing is that ads7846 chip itself just requires power supply
> Right, and the regulator API hides the non-switchability of the supply
> from the driver so there's no need for the driver to worry about how the
> supplies are wired up. It just turns the regulator on when it needs it
> and turns it off when it doesn't.
>
>>>> 1) add regulator definition for ads7846 into the board file
>>> There is no dedicated regulator on spitz, ADS7846 uses common always-on
>>> power supply.
>> Is there a kind of regulator for this case (except dummy)?
>> Some kind of fixed regulator which is not binded to any supply?
> This is just a fixed voltage regulator, support for that has been in the
> kernel since the regulator API was merged. This is the best solution,
> it ensures that you don't mistakenly activate dummy reglators for
> supplies that really need software control.

Right, just as I thought (I still haven't made myself familiar with all the
regulator API aspects).

Stanislav,
Can't you define a fixed voltage regulator for the ads7846 in spitz board file?
This shouldn't be a hard task and is the right solution from the regulator API POV.


--
Regards,
Igor.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/