| Message ID | 20200819123208.12337-8-l.stelmach@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/8] spi: spi-s3c64xx: swap s3c64xx_spi_set_cs() and s3c64xx_enable_datapath() | expand |
On Wed, Aug 19, 2020 at 02:32:07PM +0200, Łukasz Stelmach wrote: > Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com> Why? Everything works fine and suddenly minimum timeout is 100 ms? Best regards, Krzysztof > --- > drivers/spi/spi-s3c64xx.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c > index 27d77600a820..27db1e0f6f32 100644 > --- a/drivers/spi/spi-s3c64xx.c > +++ b/drivers/spi/spi-s3c64xx.c > @@ -464,7 +464,8 @@ static int s3c64xx_wait_for_dma(struct s3c64xx_spi_driver_data *sdd, > > /* millisecs to xfer 'len' bytes @ 'cur_speed' */ > ms = xfer->len * 8 * 1000 / sdd->cur_speed; > - ms += 10; /* some tolerance */ > + ms = (ms * 10) + 30; /* some tolerance */ > + ms = max(ms, 100); /* minimum timeout */ > > val = msecs_to_jiffies(ms) + 10; > val = wait_for_completion_timeout(&sdd->xfer_completion, val); > -- > 2.26.2 >
It was <2020-08-19 śro 14:49>, when Krzysztof Kozlowski wrote: > On Wed, Aug 19, 2020 at 02:32:07PM +0200, Łukasz Stelmach wrote: >> Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com> > > Why? Everything works fine and suddenly minimum timeout is 100 ms? Actually I am not 100% sure the max() call is required, maybe +30 is enough. Definitely some minimum value is required because for small tranfers (100s of bytes) ms is 0 after the first assignment. >> --- >> drivers/spi/spi-s3c64xx.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c >> index 27d77600a820..27db1e0f6f32 100644 >> --- a/drivers/spi/spi-s3c64xx.c >> +++ b/drivers/spi/spi-s3c64xx.c >> @@ -464,7 +464,8 @@ static int s3c64xx_wait_for_dma(struct s3c64xx_spi_driver_data *sdd, >> >> /* millisecs to xfer 'len' bytes @ 'cur_speed' */ >> ms = xfer->len * 8 * 1000 / sdd->cur_speed; >> - ms += 10; /* some tolerance */ >> + ms = (ms * 10) + 30; /* some tolerance */ >> + ms = max(ms, 100); /* minimum timeout */ >> >> val = msecs_to_jiffies(ms) + 10; >> val = wait_for_completion_timeout(&sdd->xfer_completion, val); >> -- >> 2.26.2 >> > >
On Wed, Aug 19, 2020 at 03:39:56PM +0200, Lukasz Stelmach wrote: > It was <2020-08-19 śro 14:49>, when Krzysztof Kozlowski wrote: > > On Wed, Aug 19, 2020 at 02:32:07PM +0200, Łukasz Stelmach wrote: > >> Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com> > > > > Why? Everything works fine and suddenly minimum timeout is 100 ms? > > Actually I am not 100% sure the max() call is required, maybe +30 is > enough. Definitely some minimum value is required because for small > tranfers (100s of bytes) ms is 0 after the first assignment. Sure, just please describe it all in commit msg. All these questions "why?" came because of lack of explanation in commit msg. I guess minimum timeout 100 ms for each transfer is quite high, so maybe just bump the tolerance to 30 which also would be a minimum timeout. Best regards, Krzysztof > > >> --- > >> drivers/spi/spi-s3c64xx.c | 3 ++- > >> 1 file changed, 2 insertions(+), 1 deletion(-) > >> > >> diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c > >> index 27d77600a820..27db1e0f6f32 100644 > >> --- a/drivers/spi/spi-s3c64xx.c > >> +++ b/drivers/spi/spi-s3c64xx.c > >> @@ -464,7 +464,8 @@ static int s3c64xx_wait_for_dma(struct s3c64xx_spi_driver_data *sdd, > >> > >> /* millisecs to xfer 'len' bytes @ 'cur_speed' */ > >> ms = xfer->len * 8 * 1000 / sdd->cur_speed; > >> - ms += 10; /* some tolerance */ > >> + ms = (ms * 10) + 30; /* some tolerance */ > >> + ms = max(ms, 100); /* minimum timeout */ > >> > >> val = msecs_to_jiffies(ms) + 10; > >> val = wait_for_completion_timeout(&sdd->xfer_completion, val); > >> -- > >> 2.26.2 > >> > > > > > > -- > Łukasz Stelmach > Samsung R&D Institute Poland > Samsung Electronics
diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c index 27d77600a820..27db1e0f6f32 100644 --- a/drivers/spi/spi-s3c64xx.c +++ b/drivers/spi/spi-s3c64xx.c @@ -464,7 +464,8 @@ static int s3c64xx_wait_for_dma(struct s3c64xx_spi_driver_data *sdd, /* millisecs to xfer 'len' bytes @ 'cur_speed' */ ms = xfer->len * 8 * 1000 / sdd->cur_speed; - ms += 10; /* some tolerance */ + ms = (ms * 10) + 30; /* some tolerance */ + ms = max(ms, 100); /* minimum timeout */ val = msecs_to_jiffies(ms) + 10; val = wait_for_completion_timeout(&sdd->xfer_completion, val);
Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com> --- drivers/spi/spi-s3c64xx.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)