On Mon, Apr 09, 2018 at 02:10:40PM +0300, Sergey Suloev wrote: > On 04/09/2018 01:50 PM, Mark Brown wrote: > > On Mon, Apr 09, 2018 at 01:26:23PM +0300, Sergey Suloev wrote: > > > Because current implementation tries to send more than FIFO-depth of data in > > > a single call to "transfer_one" which is wrong. > > No, that's absolutely not the case. All any of these functions has to > > do is transfer whatever they were asked to, how they do it is not at all > > important to the framework. > I think you don't fully understand the issue. Let's talk about sun4i and > sun6i SPI drivers separately. > sun4i > 1)it is correctly declaring max_transfer_size=FIFO depth for PIO mode but > transfer_one() function doesn't follow the declaration allowing PIO > transfers longer than FIFO depth by just refilling FIFO using 3/4 FIFO > empty interrupt. I can definitely state here that long transfers WON'T WORK > on real hardware. I tested it and that's why I can say that. But as soon as > sun4i SPI driver is correctly declaring max_transfer_size then "smart" > clients will work well by limiting a single transfer size to FIFO depth. I > tested it with real hardware, again. None of this is in the slightest bit related to the use of transfer_one() vs transfer_one_message(). These are all implementation details and will so far as I can tell apply equally to both APIs.
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