Re: [PATCH 01/10] spi: spi-axi-spi-engine: remove usage of delay_usecs
On 3/10/21 8:16 AM, Alexandru Ardelean wrote:
On Mon, 8 Mar 2021 at 18:42, Lars-Peter Clausen wrote:
On 3/8/21 3:54 PM, Alexandru Ardelean wrote:
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
---
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(>delay, xfer);
- if (delay < 0)
- return;
- delay /= 1000;
- }
+ delay = spi_delay_to_ns(>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;
Ah, true. Lets keep the code as it is.
On the other hand you could argue that we should round up to ensure the
delay is at least as long as requested. But that is something that
should be changed independently from this series.
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 wrote:
>
> On 3/8/21 3:54 PM, Alexandru Ardelean wrote:
> > 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
> > ---
> > 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(>delay, xfer);
> > - if (delay < 0)
> > - return;
> > - delay /= 1000;
> > - }
> > + delay = spi_delay_to_ns(>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;
>
> > + delay /= 1000;
> >
> > if (delay == 0)
> > return;
>
>
Re: [PATCH 01/10] spi: spi-axi-spi-engine: remove usage of delay_usecs
On 3/8/21 3:54 PM, Alexandru Ardelean wrote:
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
---
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(>delay, xfer);
- if (delay < 0)
- return;
- delay /= 1000;
- }
+ delay = spi_delay_to_ns(>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.
+ delay /= 1000;
if (delay == 0)
return;
