On Mon, Apr 11, 2016 at 01:29:06PM +0000, kernel@xxxxxxxxxxxxxxxx wrote: > From: Martin Sperl <kernel@xxxxxxxxxxxxxxxx> > > Right now the dma engine officially supports dma channel 11 and 12. > But the use of dma channel 12 immediately stalls the system. > > The reason is that the interrupt assigned right now to dma channel 11 > is actually a shared interrupt for dma channels 11 to 12. > So whenever the dma channel 12, 13 or 14 is used, it triggers the interrupt > for dma 11 which only clears the interrupt flag for dma channel 11. > This results in the interrupt 11 is triggered all the time. > > On top the requesting dma channel12 (and the corresponding irq) triggers > an immeditate stall of the system, because for the 12th interrupt > any dma channel will trigger also this interrupt - even if the dma channel > is controlled by the firmware. > > As the description in the default device-tree is (for the above reasons) > wrong a new means had to get devised that allows correct representation > of the mapping between interrupts and dma channels. > > For this the existing (but unused) device-tree property "interrupt-names" > is used to define the mapping. > > Implementing shared interrupts is another necessity when using dma channel > 11 to 14, so it is a part of this patch. Applied, thanks -- ~Vinod -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
