On Tue, Jun 12, 2012 at 10:01 AM, Girish K S <girish.shivananjappa@xxxxxxxxxx> wrote: > On 12 June 2012 14:25, Will Newton <will.newton@xxxxxxxxx> wrote: >> On Tue, Jun 12, 2012 at 5:21 AM, Girish K S >> <girish.shivananjappa@xxxxxxxxxx> wrote: >>> >>> In the Current dwmmc driver there is support for selecting IDMAC from >>> the menu config option. If the support for IDMAC is enabled in the menu >>> config and Hardware configuration register's DMA_INTERFACE field is 0. >>> Still the driver will try to do the DMA initialization. >>> >>> The dw_mci_idmac_init function currently implemented returns only success >>> indicating that the DMA initialization is always successful. The current >>> patch will add a ciheck for existance of the DMA IP and allow the >>> DMA initialization. >>> >>> Signed-off-by: Girish K S <girish.shivananjappa@xxxxxxxxxx> >>> --- >>> drivers/mmc/host/dw_mmc.c | 11 ++++++++++- >>> 1 files changed, 10 insertions(+), 1 deletions(-) >> >> This looks ok in principle. I'm wondering if we should only allow >> dma_support == 0x01 (DW_DMA) in the IDMAC case? It's not clear from >> the TRM what each of the DMA values means and I only have a system >> with external DMA support at the moment. > My understanding from the TRM > if dma_support =1; then use designware dma ip for internal > dma_support =2 then use any generic dma ip for internal dma tx > this config is only for IDMA support. If there is a external DMA CTRL > register should be used explicitly to enable DMA (there is no config > available to tell external dma supported). correct me if i am wrong. That sounds like a reasonable interpretation of the TRM. ;-) Acked-by: Will Newton <will.newton@xxxxxxxxxx> -- 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
