[U-Boot] [PATCH] spi-uclass: claim bus before setting speed

Jagan Teki jagan at amarulasolutions.com
Thu Jun 27 06:28:10 UTC 2019

On Thu, Jun 20, 2019 at 6:48 PM George Hilliard
<thirtythreeforty at gmail.com> wrote:
> The sunxi SPI peripheral driver attempts to interact with the
> peripheral in the set_speed function.  It also resets the device
> completely (disabling clocks and power) when the bus is released and

We do set_speed even before this, during spi_get_bus_and_cs call. I
don't think claim would have any effect here. and the set_speed here
is to update if speed is diff b/w slave and the actual.

If claim required here, this would also need during
spi_get_bus_and_cs, but this isn't the case.

> turns it back on when claiming.  So, if the clock was set up before
> the bus was claimed, the speed change would have no effect, and the
> peripheral wouldn't work in many cases.

Can you listed these cases, or some kind of non-working or no effect
case would help here.

More information about the U-Boot mailing list