[PATCH] ARM: OMAP2+: Fix DMA hang after off-idle

[Sebastian Reichel]

On Fri, May 16, 2014 at 02:05:35PM -0700, Tony Lindgren wrote:
> Commit 6ddeb6d84459 (dmaengine: omap-dma: move IRQ handling to omap-dma)
> added support for handling interrupts in the omap dmaengine driver
> instead of the legacy driver. Because of different handling for
> interrupts this however caused omap3 to hang eventually after hitting
> off-idle.
> 
> Any of the virtual 32 DMA channels can be assigned to any of the
> four DMA interrupts. So commit 6ddeb6d84459 made the omap dmaengine
> driver to use the second DMA interrupt while keeping the legacy code
> still using the first DMA interrupt.
> 
> This means we need to save and restore both IRQENABLE_L1 in addition
> to IRQENABLE_L0. As there is a chance that the DSP might be using
> IRQENABLE_L2 or IRQENABLE_L3 lines, let's not touch those until
> this has been confirmed. Let's just add a comment to the code for
> now.
> 
> Fixes: 6ddeb6d84459 (dmaengine: omap-dma: move IRQ handling to omap-dma)
> Cc: Russell King <rmk+kernel at arm.linux.org.uk>
> Signed-off-by: Tony Lindgren <tony at atomide.com>

I can confirm the omap3 hang after hitting off-idle and I can
confirm, that this patch fixes the problem.

Tested-By: Sebastian Reichel <sre at kernel.org>

-- Sebastian
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