Re: ETHTOOL_GSET IOCTL on GigE links
Jeff Haran wrote: With 10/100 Mbps links it wasn't such an issue since the devices tend to support the same forced speeds and duplexities as they are capable of negotiating, but with GigE links that's not always the case, at least not according to what I've read. For instance, the following doc from Sun http://www.sun.com/blueprints/0704/817-7526.pdf says that IEEE 802.3ab says you can't force 1000Base-T over copper media (see page 4), whereas some other physical media allow GigE to run without autonegotiation (there's apparently this serdes interface that allows it, for instance). Seems like there should be another field named something like supported_forced to indicate what can be forced on the interface. Either that or some more SUPPORTED_* bits to indicate supported forced modes. The 'supported' field has nothing at all to do with auto-negotiation. The driver should list all possibilities in that field, even if some are ONLY supported via 'forced' selection. Jeff P.S. [EMAIL PROTECTED] is a far more active list, and is where the network stack/driver developers appear. - To unsubscribe from this list: send the line unsubscribe netdev in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: ETHTOOL_GSET IOCTL on GigE links
From: Jeff Haran [EMAIL PROTECTED] Date: Fri, 1 Jun 2007 15:51:18 -0700 OK, but my question remains. In the case where a device supports one set of speeds via autonegotiation and another set via forcing, how does one tell which speeds can be forced and which can be autonegotiated? Unfortunately, as you have noted, this information is not given at the moment. I got bit by this the other week when I wanted to try forcing gigabit on a tg3 and the driver wouldn't allow it because it only allows forcing link speeds at 10/100 on copper links. - To unsubscribe from this list: send the line unsubscribe netdev in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: ETHTOOL_GSET IOCTL on GigE links
-Original Message- From: Jeff Garzik [mailto:[EMAIL PROTECTED] Sent: Friday, June 01, 2007 3:40 PM To: Jeff Haran Cc: [EMAIL PROTECTED]; netdev Subject: Re: ETHTOOL_GSET IOCTL on GigE links Jeff Haran wrote: With 10/100 Mbps links it wasn't such an issue since the devices tend to support the same forced speeds and duplexities as they are capable of negotiating, but with GigE links that's not always the case, at least not according to what I've read. For instance, the following doc from Sun http://www.sun.com/blueprints/0704/817-7526.pdf says that IEEE 802.3ab says you can't force 1000Base-T over copper media (see page 4), whereas some other physical media allow GigE to run without autonegotiation (there's apparently this serdes interface that allows it, for instance). Seems like there should be another field named something like supported_forced to indicate what can be forced on the interface. Either that or some more SUPPORTED_* bits to indicate supported forced modes. The 'supported' field has nothing at all to do with auto-negotiation. The driver should list all possibilities in that field, even if some are ONLY supported via 'forced' selection. Jeff OK, but my question remains. In the case where a device supports one set of speeds via autonegotiation and another set via forcing, how does one tell which speeds can be forced and which can be autonegotiated? Thanks, Jeff Haran - To unsubscribe from this list: send the line unsubscribe netdev in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: ETHTOOL_GSET IOCTL on GigE links
Jeff Haran wrote: OK, but my question remains. In the case where a device supports one set of speeds via autonegotiation and another set via forcing, how does one tell which speeds can be forced and which can be autonegotiated? The interface does not currently support such enumeration. You can certainly attempt forcing a speed, and see what happens. The driver will either (a) work, (b) refuse and give you an error message, or (c) present you with a situation that requires filing a driver bug report :) Jeff - To unsubscribe from this list: send the line unsubscribe netdev in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: ETHTOOL_GSET IOCTL on GigE links
-Original Message- From: Jeff Garzik [mailto:[EMAIL PROTECTED] Sent: Friday, June 01, 2007 4:05 PM To: Jeff Haran Cc: [EMAIL PROTECTED]; netdev Subject: Re: ETHTOOL_GSET IOCTL on GigE links Jeff Haran wrote: OK, but my question remains. In the case where a device supports one set of speeds via autonegotiation and another set via forcing, how does one tell which speeds can be forced and which can be autonegotiated? The interface does not currently support such enumeration. You can certainly attempt forcing a speed, and see what happens. The driver will either (a) work, (b) refuse and give you an error message, or (c) present you with a situation that requires filing a driver bug report :) Jeff Are there any plans in the works to modify the interface to provide this information? Thanks, Jeff Haran - To unsubscribe from this list: send the line unsubscribe netdev in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
