[U-Boot] [PATCH] spi: prevent overriding established bus settings

[Simon Glass]

On Thu, 21 Nov 2019 at 04:45, Marcin Wojtas <mw at semihalf.com> wrote:
>
> The SPI stack relies on a proper bus speed/mode configuration
> by calling dm_spi_claim_bus(). However the hitherto code
> allowed to accidentally override those settings in
> the spi_get_bus_and_cs() routine.
>
> The initially established speed could be discarded by using
> the slave platdata, which turned out to be an issue on
> the platforms whose slave maximum supported frequency
> is not on par with the maximum frequency of the bus controller.
>
> This patch fixes above issue by configuring the bus from
> spi_get_bus_and_cs() only in case it was not done before.
>
> Signed-off-by: Marcin Wojtas <mw at semihalf.com>
> ---
>  drivers/spi/spi-uclass.c | 20 +++++++++++---------
>  1 file changed, 11 insertions(+), 9 deletions(-)

Reviewed-by: Simon Glass <sjg at chromium.org>