Messages in this thread | | | Date | Thu, 25 Mar 2010 23:37:14 +0100 (CET) | From | Guennadi Liakhovetski <> | Subject | Re: [PATCH 2/2] DMAENGINE: generic channel status |
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On Thu, 25 Mar 2010, Dan Williams wrote:
> On Thu, Mar 25, 2010 at 1:58 PM, Guennadi Liakhovetski > <g.liakhovetski@gmx.de> wrote: > > On Thu, 25 Mar 2010, Linus Walleij wrote: > > > >> Convert the device_is_tx_complete() operation on the > >> DMA engine to a generic device_tx_status()operation which > >> can return three states, DMA_TX_RUNNING, DMA_TX_COMPLETE, > >> DMA_TX_PAUSED. > >> > [..] > > General: you converted all drivers to the new .device_tx_status() API, but > > since they don't implement "residue," you left it uninitialised > > everywhere. Wouldn't it be better to set it to 0 or total length, > > depending on the complete / not complete status? > > Agree that it should not be uninitialized. At the same time I do not > want to require drivers that don't need it to go through the hassle of > looking up a byte count, so perhaps all but the drivers that want this > support can return a 'max byte count'??
Why not assign one of the two - 0 if the transfer is complete (DMA_SUCCESS status returned) or whatever max count otherwise? Except I do think this might confuse some users - seeing a residue larger than the total transfer length...
Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/
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