[PATCH V2] spi: Update speed/mode on change

Marek Vasut marex at denx.de
Mon Mar 29 03:32:51 CEST 2021

On 3/28/21 11:30 PM, Tom Rini wrote:
> On Fri, Feb 26, 2021 at 03:21:24PM +0100, Marek Vasut wrote:
>> The spi_get_bus_and_cs() may be called on the same bus and chipselect
>> with different frequency or mode. This is valid usecase, but the code
>> fails to notify the controller of such a configuration change. Call
>> spi_set_speed_mode() in case bus frequency or bus mode changed to let
>> the controller update the configuration.
>> The problem can easily be triggered using the sspi command:
>> => sspi 0:0 at 1000
>> => sspi 0:0 at 2000
>> Without this patch, both transfers happen at 1000 Hz. With this patch,
>> the later transfer happens correctly at 2000 Hz.
>> Signed-off-by: Marek Vasut <marex at denx.de>
>> Cc: Jagan Teki <jagan at amarulasolutions.com>
>> Cc: Patrick Delaunay <patrick.delaunay at st.com>
> So, very reliably I can make:
> https://source.denx.de/u-boot/u-boot/-/jobs/245517
> happen locally as well building with clang.  It's not obvious to me why
> the test now fails however.

Can you please be more specific / clear ? I have no idea what those 300 
lines of cryptic output mean, nor what are you trying to say by the 
above, sorry.

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