On Wed, Jul 18, 2012 at 12:40 PM, Tony Lindgren <tony@xxxxxxxxxxx> wrote: > * Shilimkar, Santosh <santosh.shilimkar@xxxxxx> [120718 00:09]: >> On Wed, Jul 18, 2012 at 12:29 PM, Tony Lindgren <tony@xxxxxxxxxxx> wrote: >> > * Javier Martinez Canillas <javier@xxxxxxxxxxxx> [120716 23:56]: >> >> On Tue, Jul 17, 2012 at 8:45 AM, Shilimkar, Santosh >> >> <santosh.shilimkar@xxxxxx> wrote: >> >> > Hi, >> >> > >> >> > On Tue, Jul 17, 2012 at 6:00 AM, Javier Martinez Canillas >> >> > <javier@xxxxxxxxxxxx> 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@xxxxxxxxxxxx> >> >> >> --- >> >> > 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. > > I think it should rather be that if the driver is broken and does not work > without DMA, it should have depends on CONFIG_DMA_OMAP. > I can confirm that omap MMC can't work without DMA; polled mode is not supported / implemented. -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
