Hi, On Wed, Jul 4, 2012 at 4:46 PM, Paul Walmsley <paul@xxxxxxxxx> wrote: > On Wed, 9 May 2012, Kishon Vijay Abraham I wrote: > >> The DMADISABLE bit is a semi-automatic bit present in sysconfig register >> of some modules. When the DMA must perform read/write accesses, the >> DMADISABLE bit is cleared by the hardware. But when the DMA must stop for power >> management, software must set the DMADISABLE bit back to 1. >> >> In cases where the ROMCODE/BOOTLOADER uses dma, the hardware clears the >> DMADISABLE bit (but the romcode/bootloader might not set it back to 1). >> In order for the kernel to start in a clean state, it is >> necessary for the kernel to set DMADISABLE bit back to 1 (irrespective >> of whether it's been set to 1 in romcode or bootloader). >> >> During _reset of the (hwmod)device, the DMADISABLE bit is set so that it >> does not prevent idling of the system. (NOTE: having DMADISABLE to 0, >> prevents the system to idle) >> >> DMADISABLE bit is present in usbotgss module of omap5. >> >> Cc: Benoit Cousson <b-cousson@xxxxxx> >> Cc: Kevin Hilman <khilman@xxxxxx> >> Cc: Paul Walmsley <paul@xxxxxxxxx> >> Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx> > > Thanks for the detailed comments and the kerneldoc. This one has been > updated to apply and also to resolve some checkpatch warnings. Updated > patch below. Thanks :-) -Kishon -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
