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authorTimur Tabi <timur@freescale.com>2008-09-19 04:16:19 -0700
committerDan Williams <dan.j.williams@intel.com>2008-09-19 04:16:19 -0700
commit6b3141962dc82cfe1c30afdf91d564b309859cbe (patch)
tree51a0045ba900f44083fbd2693824414262534dbc /drivers/dma/dmatest.c
parent89f72a0633d1d4f28c4c5c8831ec814523d7671a (diff)
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 <haavard.skinnemoen@atmel.com> Signed-off-by: Timur Tabi <timur@freescale.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/dma/dmatest.c')
-rw-r--r--drivers/dma/dmatest.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c
index a08d19704743..422500c6c163 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);