[U-Boot] [PATCH] spi: tegra20: fix mode selection logic

[Stephen Warren]

On 08/15/2016 09:35 AM, Stephen Warren wrote:
> On 08/13/2016 09:56 AM, Jagan Teki wrote:
>> On 13 August 2016 at 02:36, Stephen Warren <swarren at wwwdotorg.org> wrote:
>>> From: Stephen Warren <swarren at nvidia.com>
>>>
>>> When the set_mode() function runs, the SPI bus is not active, and hence
>>> the clocks to the SPI controller are not running. Any register
>>> read/write
>>> at this time will hang the CPU. Remove the code from set_mode() that
>>> does
>>> this, and move it to the correct place in claim_bus().
>>
>> The idea of claim_bus is just to enable the bus for any transaction to
>> start, since set_mode is running before claim (ex: spi_get_bus_and_cs
>> while 'sf probe') it's .probe which actual driver binding
>> responsibility to initialize the SPI bus so-that .set_mode and
>> .set_speed will set the mode and freq for that initialized bus based
>> on the inputs from user, drivers like zynq, exynos will follow the
>> same.
>
> I'd rather not re-structure the driver, and to be honest I see no point
> in mandating that drivers activate their clocks/resets in probe rather
> than solely during the actual SPI transaction.
>
> Anyway, if the patch I sent isn't acceptable, please can you simply
> revert the patch it fixes so that SPI on Tegra works again? Thanks.

It turns out that getting the clocks going in probe() is pretty easy. 
I've sent a patch to do that, so this patch can be dropped.