Messages in this thread Patch in this message | | | From | Timur Tabi <> | Subject | [PATCH] dmatest: properly handle duplicate DMA channels | Date | Thu, 18 Sep 2008 10:21:19 -0500 |
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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.
Signed-off-by: Timur Tabi <timur@freescale.com> --- drivers/dma/dmatest.c | 7 ++++++- 1 files changed, 6 insertions(+), 1 deletions(-)
diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c index a08d197..2689d90 100644 --- a/drivers/dma/dmatest.c +++ b/drivers/dma/dmatest.c @@ -321,10 +321,15 @@ static void dmatest_cleanup_channel(struct dmatest_chan *dtc) static enum dma_state_client dmatest_add_channel(struct dma_chan *chan) { - struct dmatest_chan *dtc; + struct dmatest_chan *dtc, *_dtc; struct dmatest_thread *thread; unsigned int i; + /* Have we already been told about this channel? */ + list_for_each_entry_safe(dtc, _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); -- 1.5.5
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