Replace the client registration infrastructure with a custom loop to
poll for channels. Once dma_request_channel returns NULL stop asking
for channels. A userspace side effect of this change if that loading
the dmatest module before loading a dma driver will result in no
channels being found, previously dmatest would get a callback. To
facilitate testing in the built-in case dmatest_init is marked as a
late_initcall. Another side effect is that channels under test can not
be used for any other purpose.
Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
33df8ca068