Messages in this thread | | | Date | Sat, 20 Sep 2008 14:40:40 -0700 | From | "Dan Williams" <> | Subject | Re: [PATCH] dmatest: properly handle duplicate DMA channels |
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On Fri, Sep 19, 2008 at 4:31 PM, Andrew Morton <akpm@linux-foundation.org> wrote: > On Thu, 18 Sep 2008 10:21:19 -0500 > Timur Tabi <timur@freescale.com> wrote: > >> --- 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); > > hm. A few lines after that GFP_ATOMIC the driver does a GFP_KERNEL > allocation. > > One of them is incorrect. The interface is undocumented (natch), but I > assume that GFP_KERNEL is the one to use here. >
The interface is documented, although not the locking (natch), at include/linux/dmaengine.h:229. When I fix this up is there a canonical location to document a callback interface rather than at the callback's typedef?
Thanks, Dan
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