On 03/19/2018 12:56 PM, Marek Vasut wrote: > On 03/19/2018 11:53 AM, Geert Uytterhoeven wrote: >> Hi Marek, >> >> On Mon, Mar 19, 2018 at 10:53 AM, Marek Vasut <marek.vasut@xxxxxxxxx> wrote: >>> On 03/19/2018 09:38 AM, Simon Horman wrote: >>>> On Sun, Mar 18, 2018 at 11:52:52AM +0100, Marek Vasut wrote: >>>>> The data link active signal usually takes ~20 uSec to be asserted, >>>>> poll the bit more often to avoid useless delays in this function. >>>>> >>>>> Signed-off-by: Marek Vasut <marek.vasut+renesas@xxxxxxxxx> >>>>> Cc: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> >>>>> Cc: Phil Edworthy <phil.edworthy@xxxxxxxxxxx> >>>>> Cc: Simon Horman <horms+renesas@xxxxxxxxxxxx> >>>>> Cc: Wolfram Sang <wsa@xxxxxxxxxxxxx> >>>>> Cc: linux-renesas-soc@xxxxxxxxxxxxxxx >>>> >>>> Unless my eyes deceive me this seems to be quite a lot (100x) more often, >>>> but so be it. >>> >>> It's just a higher frequency to avoid slowdown when bringing the link up. >> >> No it isn't: you replaced a sleep by a delay, thus making it blocking. > > For much shorter period of time. > >> So this can spin for up to 50 ms (+ overhead)? > > That's what it did before too , it used msleep and now it uses udelay. > msleep() does not spin, it reschedules the process. Instead to find a balance you may want to play with usleep_range(). -- With best wishes, Vladimir
