| Message ID | 20250318104659.1114340-9-jerome.forissier@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | Uthreads | expand |
On Tue, 18 Mar 2025 at 12:47, Jerome Forissier <jerome.forissier@linaro.org> wrote: > > Introduce a uthread scheduling loop into udelay() when CONFIG_UTHREAD > is enabled. This means that any uthread calling into udelay() may yield > to uthread and be scheduled again later. There is no delay in the > scheduling loop because tests have shown that such a delay can have a > detrimental effect on the console (input drops characters). > > Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org> > --- > lib/time.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/lib/time.c b/lib/time.c > index d88edafb196..0e9b079f9cf 100644 > --- a/lib/time.c > +++ b/lib/time.c > @@ -17,6 +17,7 @@ > #include <asm/global_data.h> > #include <asm/io.h> > #include <linux/delay.h> > +#include <uthread.h> > > #ifndef CFG_WD_PERIOD > # define CFG_WD_PERIOD (10 * 1000 * 1000) /* 10 seconds default */ > @@ -197,7 +198,13 @@ void udelay(unsigned long usec) > do { > schedule(); > kv = usec > CFG_WD_PERIOD ? CFG_WD_PERIOD : usec; > - __udelay(kv); > + if (CONFIG_IS_ENABLED(UTHREAD)) { > + ulong t0 = timer_get_us(); > + while (timer_get_us() - t0 < kv) > + uthread_schedule(); > + } else { > + __udelay(kv); > + } > usec -= kv; > } while(usec); > } > -- > 2.43.0 > Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
diff --git a/lib/time.c b/lib/time.c index d88edafb196..0e9b079f9cf 100644 --- a/lib/time.c +++ b/lib/time.c @@ -17,6 +17,7 @@ #include <asm/global_data.h> #include <asm/io.h> #include <linux/delay.h> +#include <uthread.h> #ifndef CFG_WD_PERIOD # define CFG_WD_PERIOD (10 * 1000 * 1000) /* 10 seconds default */ @@ -197,7 +198,13 @@ void udelay(unsigned long usec) do { schedule(); kv = usec > CFG_WD_PERIOD ? CFG_WD_PERIOD : usec; - __udelay(kv); + if (CONFIG_IS_ENABLED(UTHREAD)) { + ulong t0 = timer_get_us(); + while (timer_get_us() - t0 < kv) + uthread_schedule(); + } else { + __udelay(kv); + } usec -= kv; } while(usec); }
Introduce a uthread scheduling loop into udelay() when CONFIG_UTHREAD is enabled. This means that any uthread calling into udelay() may yield to uthread and be scheduled again later. There is no delay in the scheduling loop because tests have shown that such a delay can have a detrimental effect on the console (input drops characters). Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org> --- lib/time.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)