Hello. On 02/04/2013 08:02 PM, Felipe Balbi wrote:
>>> On Mon, Feb 04, 2013 at 08:36:38PM +0300, Sergei Shtylyov wrote: >>>>> opted out of it. From the top of my head we have CPPI 3.x, CPPI 4.1, >>>>> Inventra DMA, OMAP sDMA and ux500 DMA engines supported by the driver. >>>>> Granted, CPPI 4.1 makes some assumptions about the fact that it's >>>>> handling USB tranfers, >>>> What CPPI 4.1 code makes this assumptions? MUSB DMA driver? Then it's >>>> just >>> HW makes the asumptions >> Not true at all. There is a separate set of registers (at offset 0) which >> copes with USB specifics, but CPPI 4.1 itself doesn't know about USB >> anything. > CPPI 4.1 was made for USB transfers. Utter nonsense, CPPI 4.1 is hardware abstract DMA engine. It's used for Ethernet transfers on out-of-tree platforms like mach-avalanche/. >> It's just the way the driver was written that it used both sets of registers >> but >> this needs to be changed into more abstacted accesses to the USB-specific >> part, >> to cope with it being different on different platfroms, like AM35x. The >> driver >> as it was last posted, just needs rework now. > are you saying you will do the work ? My efforts stopped to be funded by MV back in 2010. Hell, I'm not even working in MV as I used to, hanging on the verge of my current contract being terminated. >>>> Don't know, I was quite content with the abstraction when writing CPPI >>>> 4.1 >>>> driver for MUSB... >>> look closer. The whole: >>> if (is_cppi()) >>> foo(); >>> else if (is_inventra()) >>> bar(); >>> else if (is_omap_sdma()) >>> baz(); >>> is bogus. >> That part -- yes. There were attempt to get rid of this, but without >> changing >> the DMA API. It was left halfway done after my only critical comment, IIRC. >> Will >> we ever see the continuation of this effort? > patches are welcome There was a patch, it only needed comments addressed. I think the author was Heikki Krogerus. As for me, my time is very limited, so be thankful even for those scarce patches I'm sending out now -- I'm doing them in my copious free time. WBR, Sergei -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
