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Subject[PATCH RFC] clk: ux500: add range to usleep_range
Providing a range for usleep_range() allows the hrtimer subsystem to
coalesce timers - the delay is runtime configurable so a factor 2
is taken to provide the range.

Signed-off-by: Nicholas Mc Guire <>

Problem located with an experimental coccinelle script

Q: Basically usleep_range() with min == max never makes much sense notably
in non-atomic context. If the factor of 2 is tolerable or a fixed
offset of e.g. 1000 would be more suitable is not clear to me - maybe
someone familiar with that driver can clarify this.

Patch was compile tested with: u8500_defconfig (implies COMMON_CLK=y)
(with some sparse warnings about not implemented system calls)

Patch is against 5.1-rc3 (localversion-next is next=20190405)

drivers/clk/ux500/clk-sysctrl.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clk/ux500/clk-sysctrl.c b/drivers/clk/ux500/clk-sysctrl.c
index 7c0403b..a1fa3fb 100644
--- a/drivers/clk/ux500/clk-sysctrl.c
+++ b/drivers/clk/ux500/clk-sysctrl.c
@@ -42,7 +42,7 @@ static int clk_sysctrl_prepare(struct clk_hw *hw)

if (!ret && clk->enable_delay_us)
- usleep_range(clk->enable_delay_us, clk->enable_delay_us);
+ usleep_range(clk->enable_delay_us, clk->enable_delay_us*2);

return ret;
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