Messages in this thread | | | From | Arnd Bergmann <> | Subject | Re: [PATCH 1/2] dma: of: Remove restriction that #dma-cells can't be 0 | Date | Mon, 22 Apr 2013 14:38:15 +0200 |
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On Monday 22 April 2013, Lars-Peter Clausen wrote: > > There is no sensible reason why #dma-cells shouldn't be allowed to be 0. It is > completely up to the DMA controller how many additional parameters, besides the > phandle, it needs to identify a channel. E.g. for DMA controller with only one > channel or for DMA controllers which don't have a restriction on which channel > can be used for which peripheral it completely legitimate to not require any > additional parameters. > > Also fixes the following warning: > drivers/dma/of-dma.c: In function 'of_dma_controller_register': > drivers/dma/of-dma.c:67:7: warning: 'nbcells' may be used uninitialized in this function > > Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Do you have an example for this? If a dma engine has only one request line, why would you even use the dmaengine subsystem for it, rather than including the code to program it in the slave driver?
Arnd
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