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Re: [PATCH v2] dmatest: properly handle duplicate DMA channels

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From: Timur Tabi
Subject: [PATCH v2] dmatest: properly handle duplicate DMA channels
Date: Thursday, September 18, 2008 - 9:10 am

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>
---

Replaced list_for_each_entry_safe() with list_for_each_entry()

 drivers/dma/dmatest.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c
index a08d197..422500c 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);
-- 
1.5.5

--


[ message continues ]
[view original message]
From: Haavard Skinnemoen
Subject: Re: [PATCH v2] dmatest: properly handle duplicate DMA channels
Date: Thursday, September 18, 2008 - 9:16 am

Acked-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
--


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Previous thread: [git patches] new network drivers for net-next by Jeff Garzik on Thursday, September 18, 2008 - 9:00 am. (7 messages)

Next thread: [PATCH] fsl-dma: allow Freescale Elo DMA driver to be compiled as a module by Timur Tabi on Thursday, September 18, 2008 - 9:24 am. (4 messages)