On Fri, Nov 23, 2007 at 04:34:36PM +0100, Haavard Skinnemoen wrote: > This client tests DMA memcpy using various lengths and various offsets > into the source and destination buffers. It will initialize both > buffers with a know pattern and verify that the DMA engine copies the > requested region and nothing more. > > Signed-off-by: Haavard Skinnemoen <[EMAIL PROTECTED]>
Hi, First of all: Thanks for sharing this, it's quite useful! I've been playing around with this a bit today, and I've been seeing some odd behaviour. It seems that once a channel is allocated to dmatest, it will never be freed, i.e. the drivers device_free_chan_resources will never be called on it. Looking at the dma stack, I'm not sure just where it's expected to happen. Once the channel is allocated, the dma_chan_get/put calls all just modify the per-cpu variables, and nothing will ever boil down to a call to kref_put() of the refcount until the _driver_ is deregistered. Not even deregistering the client seems to do it. Or am I missing something here? Shannon? Dan? I happened to catch it due to a BUG_ON() in my device_alloc_chan_resources that checked to make sure it wasn't allocated twice without a free inbetween. It hit on the second load of the dmatest module, since they were never freed on unload. -Olof -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
