[PATCH 1/1] mmc: host: enable OMAP DMA engine support for omap hosts by default

[Shilimkar, Santosh]

On Wed, Jul 18, 2012 at 12:29 PM, Tony Lindgren <tony at atomide.com> wrote:
> * Javier Martinez Canillas <javier at dowhile0.org> [120716 23:56]:
>> On Tue, Jul 17, 2012 at 8:45 AM, Shilimkar, Santosh
>> <santosh.shilimkar at ti.com> wrote:
>> > Hi,
>> >
>> > On Tue, Jul 17, 2012 at 6:00 AM, Javier Martinez Canillas
>> > <javier at dowhile0.org> wrote:
>> >> The OMAP MMC and OMAP High Speed MMC hosts now use entirely the DMA
>> >> engine API instead of the previous private DMA API implementation.
>> >>
>> >> So, if the kernel is built with support for any of these hosts but it
>> >> doesn't support DMA devices nor OMAP DMA support, it fails when trying
>> >> to obtain a DMA channel which leads to the following error on an OMAP3
>> >> IGEPv2 Rev.C board (and probably on most OMAP boards with MMC support):
>> >>
>> >> [    2.199981] omap_hsmmc omap_hsmmc.1: unable to obtain RX DMA engine channel 48
>> >> [    2.215087] omap_hsmmc omap_hsmmc.0: unable to obtain RX DMA engine channel 62
>> >>
>> >> selecting automatically CONFIG_DMADEVICES and CONFIG_DMA_OMAP solves it.
>> >>
>> >> Signed-off-by: Javier Martinez Canillas <javier at dowhile0.org>
>> >> ---
>> > Considering, we are updating drivers to select the DMA engine, can you
>> > also include
>> > "drivers/spi/spi-omap2-mcspi.c" which is also updated for DMA engine.
>> >
>> > Regards
>> > Santosh
>>
>> Hi Santosh,
>>
>> Ok, I'll send a v2 now which includes spi-omap2-mcspi then.
>
> I don't think we should do this, the drivers should work with and without
> dma. This just needs to be added to the omap2plus_defconfig.
>
Well this was not decided based on any DMA CONFIG option before for
the subject drivers. It is already by default enabled if the DMA is supported
by the driver IP. There is a possibility to disable it from driver platform/dt
data so that still remains.

Regards
Santosh