Re: [PATCH 0/3] dmaengine: bcm2835: support dma channel 11 to 14

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On Thu, Mar 17, 2016 at 03:24:30PM +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.

This looks fine by me, need an ACK on ARM patch before this can be applied.

-- 
~Vinod
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Device Tree Compilter]     [Device Tree Spec]     [Linux Driver Backports]     [Video for Linux]     [Linux USB Devel]     [Linux PCI Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Yosemite Backpacking]
  Powered by Linux