Hi Sascha, Le Fri, 7 Sep 2012 09:47:34 +0200, Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> a écrit : > On Fri, Sep 07, 2012 at 09:30:00AM +0200, Eric Bénard wrote: > > Hi Sascha, > > > > Le Fri, 7 Sep 2012 08:57:03 +0200, > > Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> a écrit : > > > > > Hi Eric, > > > > > > On Thu, Sep 06, 2012 at 09:39:29PM +0200, Eric Bénard wrote: > > > > this saves some time during boot when ethernet is not needed in barebox > > > > > > Is this really significant on your hardware? I made a measurement here > > > and the miidev_restart_aneg() takes 130us on an i.MX27 board. > > > > > > The original intention of doing it at init time was that autonegotation > > > is already completed when we actually use the network. And this time > > > really is significant: > > > > > > without the patch: > > > > > > barebox@Phytec phyCORE-i.MX27:/ time ping 192.168.23.4 > > > warning: No MAC address set. Using random address 62:FE:FE:0B:09:A8 > > > phy0: Link is up - 100/Full > > > host 192.168.23.4 is alive > > > time: 10ms > > > > > > with the patch: > > > > > > barebox@Phytec phyCORE-i.MX27:/ time ping 192.168.23.4 > > > warning: No MAC address set. Using random address A6:1B:AB:80:FA:E7 > > > phy0: Link is up - 100/Full > > > host 192.168.23.4 is alive > > > time: 2040ms > > > > > that strange. I don't see why miidev_restart_aneg() would take less > > time at boot than at open. > > Well, it does not really take longer. The difference is that if you are > sitting before your board it usually takes a few seconds to interrupt > autoboot, think what you want to do, and finally enter some network > command. In the meantime autonegotiation will be complete. If we start > autonegotiation at open time, we will always have to wait for the full > autonegotiation time after starting the first network command. > I didn't check but on my board, the problem may be similar to the 1G wrong detection : if miidev_restart_aneg is trying to acess the phy when the MII link is not yet initialized, then it would wait 1s for the reset to timeout in miidev_restart_aneg which would explain why I save 1s with this patch. Eric _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
