Hi Arnd, On Sat, Aug 15, 2015 at 10:26 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote: >> > How about changing the type of the slave_id_rx/slave_id_tx fields >> > to void*? That way, the hack can be moved to arch/sh/boards/board-sh7757lcr.c, >> > which is now the only file passing data this way. Ideally, we'd also >> > pass the shdma_chan_filter function pointer in pdata to avoid the link >> > time dependency on a particular dmaengine driver. >> >> That's actually more tricky, as a NULL filter function means something >> completely different, and causes funny failures if the DTS lacks "dmas" >> properties, cfr. "dmaengine: shdma: Make dummy shdma_chan_filter() always >> return false". >> https://git.kernel.org/cgit/linux/kernel/git/vkoul/slave-dma.git/commit/?h=next&id=056f6c87028544de934f27caf95aa1545d585767 > > Ah, this is nasty, I had not thought of that case. This makes the entire > dma_request_slave_channel_compat() interface (which I never liked, fwiw) > dangerous to use, because a lot of other drivers will get the filter > function pointer from pdata already (any driver that works with more > than one dmaengine master has to). > > I wonder if we should enforce this in __dma_request_slave_channel_compat() > by checking both the fn and fn_param arguments to ensure they are not > NULL before calling the legacy fallback using __dma_request_channel. Thanks, that seems to work fine. Will send a patch... Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
