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SubjectRe: [PATCH] i2c: imx: use usleep_range(50,100) instead of udelay(50)
On Tue, Apr 26, 2016 at 08:27:46AM +0200, Dirk Behme wrote:
> From: Oleksij Rempel <linux@rempel-privat.de>
>
> Documentation/timers/timers-howto.txt recommends to use
> usleep_range on delays > 10usec. According to my test results
> with Neonode zForce touchscreen driver, usleep_range indeed
> reduces CPU load.
>
> Stats collected with "./perf record -a -g -F 1000 sleep 10"
>
> i2c-imx with udelay(50):
> 34.19% 0.00% irq/220-Neonode [kernel.kallsyms] [k] irq_thread
> ---irq_thread
> |--33.75%--irq_thread_fn
> | |--19.27%--0x7f08a878
> | | i2c_master_recv
> | | i2c_transfer
> | | __i2c_transfer
> | | i2c_imx_xfer
> | | |--11.71%--i2c_imx_trx_complete

Reworded $subject to match code and applied to for-next, thanks!

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