Hi Tony, On Thursday 19 May 2016 01:00 AM, Tony Lindgren wrote: > * Peter Ujfalusi <peter.ujfalusi@xxxxxx> [160518 03:26]: >> On 05/18/16 11:45, Kishon Vijay Abraham I wrote: >>> omap hsmmc host controller has ADMA2 feature. Enable it here >>> for better read and write throughput. Add a new dt binding >>> "ti,use_adma" to enable ADMA2. >>> >>> Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx> >>> --- >>> .../devicetree/bindings/mmc/ti-omap-hsmmc.txt | 1 + >>> drivers/mmc/host/omap_hsmmc.c | 320 ++++++++++++++++---- >>> include/linux/platform_data/hsmmc-omap.h | 1 + >>> 3 files changed, 256 insertions(+), 66 deletions(-) >>> >>> diff --git a/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt b/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt >>> index 74166a0..eb5ceec2 100644 >>> --- a/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt >>> +++ b/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt >>> @@ -28,6 +28,7 @@ specifier is required. >>> dma-names: List of DMA request names. These strings correspond >>> 1:1 with the DMA specifiers listed in dmas. The string naming is >>> to be "rx" and "tx" for RX and TX DMA requests, respectively. >>> +ti,use_adma: enable adma2 feature >> >> Do we have use case when you want to fall back to generic DMA instead of aDMA2? > > Yes my guess is that PM runtime breaks with these currently.. pm_runtime_get is invoked during omap_hsmmc_request and pm_runtime_put is invoked during omap_hsmmc_request_done. Both these calls are outside DMA API's. So it shouldn't break anything w.r.t PM runtime no? > >> IMHO if the driver supports aDMA2, it is going to use it instead of the >> generic s/eDMA. >> What I mean is: >> the driver implements the aDMA2 support. >> if the IP has support for aDMA2, then it is going to use it, otherwise it will >> use the generic DMA. > > Ideally the adma support would be a separate loadable module, > similar how the cppi41dma is a child of the OTG controller. > > That way the systems wanting to use adma can just specify it > in the binding, and adma PM runtime support can be added later > on. > > Of course this won't work if the adma registers are sprinkled > within the MMC controller registers.. right, adma registers are within the MMC controller register space. Thanks Kishon -- 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
