Messages in this thread | | | Date | Tue, 26 Apr 2016 23:35:27 +0200 | From | Wolfram Sang <> | Subject | Re: [PATCH] i2c: imx: use usleep_range(50,100) instead of udelay(50) |
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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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