lkml.org 
[lkml]   [2008]   [Sep]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] dmatest: properly handle duplicate DMA channels
Date
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


\
 
 \ /
  Last update: 2008-09-18 17:25    [W:0.054 / U:0.112 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site