Re: [PATCH 01/10] spi: spi-axi-spi-engine: remove usage of delay_usecs

On Mon, 8 Mar 2021 at 18:42, Lars-Peter Clausen [off-list ref] wrote:

On 3/8/21 3:54 PM, Alexandru Ardelean wrote:

quoted

The 'delay_usecs' field was handled for backwards compatibility in case
there were some users that still configured SPI delay transfers with
this field.

They should all be removed by now.

Signed-off-by: Alexandru Ardelean <redacted>
---
  drivers/spi/spi-axi-spi-engine.c | 12 ++++--------
  1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c
index af86e6d6e16b..80c3e38f5c1b 100644
--- a/drivers/spi/spi-axi-spi-engine.c
+++ b/drivers/spi/spi-axi-spi-engine.c

@@ -170,14 +170,10 @@ static void spi_engine_gen_sleep(struct spi_engine_program *p, bool dry,
      unsigned int t;
      int delay;

-     if (xfer->delay_usecs) {
-             delay = xfer->delay_usecs;
-     } else {
-             delay = spi_delay_to_ns(&xfer->delay, xfer);
-             if (delay < 0)
-                     return;
-             delay /= 1000;
-     }
+     delay = spi_delay_to_ns(&xfer->delay, xfer);
+     if (delay < 0)
+             return;

Bit of a nit, but this could be `delay <= 0` and then drop the check for
`delay == 0` below.

hmm, that's a bit debatable, because the `delay == 0` check comes
after `delay /= 1000` ;
to do what you're suggesting, it would probably need a
DIV_ROUND_UP(delay, 1000) to make sure that even sub-microsecond
delays don't become zero;

if you're acking this suggestion i'll implement it;
i'll wait a few more days to see if there are any other acks or
complaints on the set before sending a V2;

btw: this new spi_delay struct supports delays in microseconds,
nanoseconds and clock cycles;
at some point it may be interesting to use a
`spi_delay_to_clk_cycles()` for this driver and other similar;

quoted

+     delay /= 1000;

      if (delay == 0)
              return;