Re: [Intel-wired-lan] [PATCH] e1000e: changed some expensive calls of udelay to usleep_range

[Pavel Machek]

On Thu 2017-09-07 22:19:47, Brown, Aaron F wrote:
> > From: Intel-wired-lan [mailto:intel-wired-lan-bounces@xxxxxxxxxx] On
> > Behalf Of Pavel Machek
> > Sent: Monday, September 4, 2017 9:26 AM
> > To: Matthew Tan <matthew.tan_1@xxxxxxx>
> > Cc: michael.kardonik@xxxxxxx; Williams, Mitch A
> > <mitch.a.williams@xxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx;
> > john.ronciak@xxxxxxxxx; intel-wired-lan@xxxxxxxxxxxxxxxx;
> > netdev@xxxxxxxxxxxxxxx
> > Subject: Re: [Intel-wired-lan] [PATCH] e1000e: changed some expensive calls
> > of udelay to usleep_range
> > 
> > Hi!
> > 
> > > @@ -183,7 +183,7 @@ s32 e1000e_read_phy_reg_mdic(struct e1000_hw
> > *hw, u32 offset, u16 *data)
> > >  	 * reading duplicate data in the next MDIC transaction.
> > >  	 */
> > >  	if (hw->mac.type == e1000_pch2lan)
> > > -		udelay(100);
> > > +		usleep_range(90, 100);
> > >
> > >  	return 0;
> > >  }
> > 
> > Can you explain why shortening the delay is acceptable here?
> 
> Maybe it's not.
> 
> This patch is causing speed / duplex tests to fail on several of my test systems.  Specifically a Lenova laptop with an 82577 and a NUC with an i218 (though that does not mean it is limited to those or that it's not related to the individual link partner.)
>

Ok, this should be quite easy to verify -- just adjust all the ranges
to be >= original ones.

Thanks,
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
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