On 06/24/2016 03:55 PM, Russell King - ARM Linux wrote: > 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?
In the sense that it is symetrical to the register code, probably. > > 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. > What would you suggest we do instead? Would switching to IDA/IDR give us better results for instance (I have not looked too closely yet)? -- Florian
