Commit 5df529d440("regulator: core: Reduce busy-wait looping")
can also be used in regulator_do_set_voltage.
Signed-off-by: Jonghwan Choi <jhbird.c...@samsung.com>
---
drivers/regulator/core.c | 39 +++++++++++++++++++++++++++++++++------
1 file changed, 33 insertions(+), 6 deletions(-)
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index afca1bc..c375bfb 100644
--- a/drivers/regulator/core.c
+++ b/d728099474rivers/regulator/core.c
@@ -2355,12 +2355,39 @@ static int _regulator_do_set_voltage(struct
regulator_dev *rdev,
delay = 0;
}
- /* Insert any necessary delays */
- if (delay >= 1000) {
- mdelay(delay / 1000);
- udelay(delay % 1000);
- } else if (delay) {
- udelay(delay);
+ /*
+ * Delay for the requested amount of time as per the
guidelines in:
+ *
+ * Documentation/timers/timers-howto.txt
+ *
+ * The assumption here is that regulators will never set the
voltage in
+ * atomic context and therefore sleeping functions can be
used.
+ */
+ if (delay) {
+ unsigned int ms = delay / 1000;
+ unsigned int us = delay % 1000;
+
+ if (ms > 0) {
+ /*
+ * For small enough values, handle
super-millisecond
+ * delays in the usleep_range() call below.
+ */
+ if (ms < 20)
+ us += ms * 1000;
+ else
+ msleep(ms);
+ }
+
+ /*
+ * Give the scheduler some room to coalesce with any
other
+ * wakeup sources. For delays shorter than 10 us,
don't even
+ * bother setting up high-resolution timers and just
busy-
+ * loop.
+ */
+ if (us >= 10)
+ usleep_range(us, us + 100);
+ else
+ udelay(us);
}
}
--
1.7.10.4
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