[PATCH v3 3/6] spi: sun6i: restrict transfer length in PIO-mode

Sergey Suloev ssuloev at orpaltech.com
Thu Apr 5 06:44:16 PDT 2018


On 04/05/2018 04:17 PM, Mark Brown wrote:
> On Thu, Apr 05, 2018 at 12:59:35PM +0300, Sergey Suloev wrote:
>> On 04/05/2018 12:19 PM, Maxime Ripard wrote:
>>> The point of that patch was precisely to allow to send more data than
>>> the FIFO. You're breaking that behaviour without any justification,
>>> and this is not ok.
>> I am sorry, but you can't. That's a hardware limitation.
> Are you positive about that?  Normally you can add things to hardware
> FIFOs while they're being drained so so long as you can keep data
> flowing in at least as fast as it's being consumed.

Well, normally yes, but this is not the case with the hardware that I 
own. My a20 (BPiM1+) and a31 (BPiM2) boards behaves differently. With a 
transfer larger than FIFO then TC interrupt never happens.




More information about the linux-arm-kernel mailing list