On Fri, Jun 24, 2016 at 03:44:11PM -0700, Florian Fainelli wrote: > If we have a system which uses fixed PHY devices and calls > fixed_phy_register() then fixed_phy_unregister() we can exhaust the > number of fixed PHYs available after a while, since we keep incrementing > the variable phy_fixed_addr, but we never decrement it. > > This patch fixes that by decrementing phy_fixed_addr during > fixed_phy_del(), and in order to do that, we need to move the > phy_fixed_addr integer and its spinlock above that function.
Is this really a good idea? What if we have two fixed phys register, and the first one is unregistered and a new one subsequently registered? First phy registered, gets address 0, phy_fixed_addr becomes 1. Second phy registered, gets address 1, phy_fixed_addr becomes 2. First phy is unregistered, phy_fixed_addr becomes 1. Third phy registered, gets address 1, conflicts with the second phy. Obviously not a good outcome. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net.
