Re: PM/RTC 3.5-rc5: System suspends fails when not built with RTC?

[Kevin Hilman <khilman@ti.com>]

Tony Lindgren <tony@atomide.com> writes:

> * Kevin Hilman <khilman@ti.com> [120711 14:34]:
>> Omar Ramirez Luna <omar.luna@linaro.org> writes:
>> 
>> > On 11 July 2012 12:07, Kevin Hilman <khilman@ti.com> wrote:
>> > ...
>> >>> [    2.311004] omap_hsmmc omap_hsmmc.0: Failed to get debounce clk
>> >>> [    2.317382] omap_hsmmc omap_hsmmc.0: unable to obtain RX DMA engine channel 62
>> >>> [    2.325256] omap_hsmmc omap_hsmmc.1: Failed to get debounce clk
>> >>> [    2.331512] omap_hsmmc omap_hsmmc.1: unable to obtain RX DMA engine channel 48
>> >>
>> >> These are normal because DMA engine is not compiled in with
>> >> omap2plus_defconfig.  MMC wont' work unless you build in DMA engine, but
>> >> that doesn't matter for trying to figure out your problem.
>> >
>> > Hijacking this thread a little bit...
>> >
>> > It looks like a dependency is missing in Kconfig then, as this also
>> > fails to boot if the file system is in MMC. As you pointed out
>> > CONFIG_DMADEVICES and CONFIG_DMA_OMAP is needed to boot in this case.
>> > I'm using a Panda 4460.
>> 
>> Yes, the drivers that have been converted to DMA engine should probably
>> 'select DMADEVICES' and 'select DMA_OMAP' since they will now depend on
>> DMA engine.
>
> The drivers should also work with PIO if DMADEVICES is not selected.
> If they don't it's a bug in the driver, or at least the driver probe
> should return an error.

There was definitely a bug in the MMC driver where probe was not
returning an error.  Looks like this bug has existed for awhile in the
MMC driver, and continued after the DMA engine conversion.

I sent a patch on top of Russell's DMA engine conversion (which he has
now applied in his for-next) to fix this problem in the DMA-converted
driver.

Kevin