On Wed, Jul 18, 2012 at 1:14 PM, S, Venkatraman <svenkatr@xxxxxx> wrote: > 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. Same case for SPI driver as well. It uses DMA for everything except the cases where DMA doesn't make sense like 1 byte/2 byte etc. And its not configurable, At least considering this, it is better we do this per driver than enabling it at SOC config. Regards Santosh -- 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
