Date: Tue, 17 Sep 2002 02:31:57 -0700 (PDT) From: Don Lewis <dl-freebsd@catspoiler.org> To: brandt@fokus.gmd.de Cc: dl-freebsd@catspoiler.org, phk@critter.freebsd.dk, archie@dellroad.org, bde@zeta.org.au, joe@FreeBSD.org, obrien@FreeBSD.org, cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/kern kern_timeout.c Message-ID: <200209170932.g8H9Vvwr015410@gw.catspoiler.org> In-Reply-To: <20020917111410.U812-100000@beagle.fokus.gmd.de>
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On 17 Sep, Harti Brandt wrote: > On Tue, 17 Sep 2002, Don Lewis wrote: > > DL>On 17 Sep, Harti Brandt wrote: > DL>> (2) two macros MII_SET and MII_CLR are used to fiddle with the MDIO bits. > DL>> This looks fine from an aesthetic standpoint of view, but adds some dozens > DL>> of additional operations. I introduced a MII_SETCLR macro which can set > DL>> and clear bits at the same time. This reduces the readreg time further to > DL>> 250usecs. > DL> > DL>There is a problem here. The 802.3 spec says that MDIO may not change > DL>within 10ns of the rising edge of the clock. Even if the card doesn't > DL>require strict adherence to the 802.3 timing, I'd expect that changing > DL>both at the same time would be hazardous. > > In the place where the macro is used, it clears the clock bit and sets the > data bit, so this is the falling edge of the clock, which should be ok. Ok. I had reversed the order of the arguments to the macro when I read the patch the first time. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message
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