On 06/12/2015 03:58 PM, Vinod Koul wrote: > Sorry this slipped thru I was away for a week anyways ;) > Thinking about it again, I think we should coverge to two APIs and mark the > legacy depracuated and look to convert folks and phase that out Currently, w/o this series we have these APIs: /* to be used with DT/ACPI */ dma_request_slave_channel(dev, name) /* NULL on failure */ dma_request_slave_channel_reason(dev, name) /* error code on failure */ /* Legacy mode only - no DT/ACPI lookup */ dma_request_channel(mask, fn, fn_param) /* NULL on failure */ /* to be used with DT/ACPI or legacy boot */ dma_request_slave_channel_compat(mask, fn, fn_param, dev, name) /* NULL on failure */ To request _any_ channel to be used for memcpy one has to use dma_request_channel(mask, NULL, NULL); If I did not missed something. As we need different types of parameters for DT/ACPI and legacy (non DT/ACPI lookup) and the good API names are already taken, we might need to settle: /* to be used with DT/ACPI */ dma_request_slave_channel(dev, name) /* error code on failure */ - Convert users to check IS_ERR_OR_NULL() instead against NULL - Mark dma_request_slave_channel_reason() deprecated and convert the current users /* to be used with DT/ACPI or legacy boot */ dma_request_slave_channel_compat(mask, fn, fn_param, dev, name) /* error code on failure */ - Convert users to check IS_ERR_OR_NULL() instead against NULL - Do not try legacy mode if either OF or ACPI failed because of real error /* Legacy mode only - no DT/ACPI lookup */ dma_request_channel_legacy(mask, fn, fn_param) /* error code on failure */ - convert users of dma_request_channel() - mark dma_request_channel() deprecated /* to be used to get a channel for memcpy for example */ dma_request_any_channel(mask) /* error code on failure */ - Convert current dma_request_channel(mask, NULL, NULL) users I know, any of the other function could be prepared to handle this when parameters are missing, but it is a bit cleaner to have separate API for this. It would be nice to find another name for the dma_request_slave_channel_compat() so with the new name we could have chance to rearrange the parameters: (dev, name, mask, fn, fn_param) We would end up with the following APIs, all returning with error code on failure: dma_request_slave_channel(dev, name); dma_request_channel_legacy(mask, fn, fn_param); dma_request_slave_channel_compat(mask, fn, fn_param, dev, name); dma_request_any_channel(mask); What do you think? -- Péter -- To unsubscribe from this list: send the line "unsubscribe linux-media" in
