From 6b3141962dc82cfe1c30afdf91d564b309859cbe Mon Sep 17 00:00:00 2001 From: Timur Tabi Date: Fri, 19 Sep 2008 04:16:19 -0700 Subject: [PATCH] dmatest: properly handle duplicate DMA channels Update the the dmatest driver so that it handles duplicate DMA channels properly. When a DMA client is notified of an available DMA channel, it must check if it has already allocated resources for that channel. If so, it should return DMA_DUP. This can happen, for example, if a DMA driver calls dma_async_device_register() more than once. Acked-by: Haavard Skinnemoen Signed-off-by: Timur Tabi Signed-off-by: Dan Williams --- drivers/dma/dmatest.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c index a08d1970474..422500c6c16 100644 --- a/drivers/dma/dmatest.c +++ b/drivers/dma/dmatest.c @@ -325,6 +325,11 @@ static enum dma_state_client dmatest_add_channel(struct dma_chan *chan) struct dmatest_thread *thread; unsigned int i; + /* Have we already been told about this channel? */ + list_for_each_entry(dtc, &dmatest_channels, node) + if (dtc->chan == chan) + return DMA_DUP; + dtc = kmalloc(sizeof(struct dmatest_chan), GFP_ATOMIC); if (!dtc) { pr_warning("dmatest: No memory for %s\n", chan->dev.bus_id); -- 2.41.1