Messages in this thread | | | From | Florian Fainelli <> | Date | Thu, 12 Feb 2015 06:12:26 -0800 | Subject | Re: Ethernet: how to disable gigabit support |
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2015-02-06 5:57 GMT-08:00 Pavel Machek <pavel@ucw.cz>: > On Thu 2015-02-05 14:44:55, Florian Fainelli wrote: >> On 05/02/15 12:25, Pavel Machek wrote: >> > Hi! >> > >> > This happened on more than one project: there's gigabit-capable chip, >> > but the connector is not designed for gigabit speed. >> > >> > I'd like to have speed autonegotiation, but not offer gigabit (as it >> > will not work). >> > >> > Is there way to do that without hacking the kernel? Should mii-tool do >> > that? >> >> Since you use the PHY library, you should be able to do something like >> this in your PHY driver prior to starting the PHY state machine: >> >> phydev->supported &= PHY_BASIC_FEATURES (effectively masking Gigabit >> capability) > > Thanks, that did the trick. > Pavel > (But still it would be nice to have a generic way of doing this, > using something like mii-tool.)
You can also force that by setting the "max-speed" property in the Ethernet PHY node, the PHY library will populate the supported bitmask accordingly and remove speeds which are not supposed to be supported.
I have to admit it has been a while since I used mii-tool, so the ioctl() side on the PHY library might be off. -- Florian
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