[PATCH 4/6] spi/spi-pl022: calculate_effective_freq() must set rate <= requested rate

[Probably you missed reply-all by mistake, so adding them again]

On 08/10/2011 01:34 AM, Linus Walleij wrote:

On Tue, Aug 9, 2011 at 1:05 PM, Viresh Kumar [off-list ref] wrote:

quoted

There were few issues with calculate_effective_freq() routine:
- It was returning first rate found >= requested rate. Now, if system have spi's
 rate as 83 MHz, with possible prescaled rates as 83, 41.5, 20.75, 13.83 (as we
 can prescale with multiples of 2). If user has given rate to be programmed as
 22 MHz, then driver programmes it to 41.5 MHz. This looks to be incorrect, as
 user might have given the upper limit of the device, and we are programming it
 above it.
- Driver finds the first satisfying rate and programmes it, but with other
 values of scr & cpsdvsr, it is possible to get more closer rate.

Good that you found this bug!

quoted

+#define SPI_RATE(rate, cpsdvsr, scr)   (rate / (cpsdvsr * (1 + scr)))

Can you use a static inline instead of a macro? It is often preferred.
If you do, this is Acked-by.

Not a problem. Will surely do that.

-- 
viresh