On 09/13/2012 06:38 PM, Russell King - ARM Linux wrote: > On Thu, Sep 13, 2012 at 05:27:09PM +0200, Lars-Peter Clausen wrote: >> Hm... Do you think it would work as well if we implement this by setting the >> callback for the descriptor to NULL? If the callback is NULL there is >> nothing to at the end of a transfer/period and the dma engine driver may >> choose to disable interrupts. This would also benefit non cyclic transfers >> where the callback is NULL and we do not need add the new parameter to >> dmaengine_prep_dma_cyclic. > > Actually, there's a way to do that already. DMA_PREP_INTERRUPT. > Unfortunately, most DMA engine slave API users don't set it when they > setup their transfer: > > * @DMA_PREP_INTERRUPT - trigger an interrupt (callback) upon completion of > * this transaction As I mentioned already to Vinod: the description of this flag is close enough for our needs (other than the notion of 'this transaction' is not really correct for cyclic mode). I will resend the series to add the flags as new parameter instead of the no_wakeup. > > if we fixed that, then we could use the lack of it to avoid the interrupt. > > However, cyclic transfers don't have the flags parameter used to pass this > bit. Yet another bit of yucky inconsistent design in DMA engine land... > -- Péter -- 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
