On 17/02/14 20:48, Florian Fainelli wrote: [snip]
- fixing up some design mistake? - accounting for a specific board design?Kind of both. This was invented to defy the necessity of having platform fixup in the DT case (where there should be no board file to place it into). I have already described that platform fixup necessary on the Renesas Lager/Koelsch boards where the LED0 signat is connected to ETH_LINK signal on the SoC and the PHY reset sets the LED control bits to default 0 which means that LED0 will be LINK/ACTIVITY signal and thus blink on activity and cause ETH_LINK to bounce off/on after each packet.In any case a PHY fixup would do the job for you.Not in any case. In case of DT we have no place for it, so should invent something involving DT.How is DT different than any machine probing mechanism here? The way to involve DT is to do the following: if (of_machine_is_compatible("renesas,foo-board-with-broken-micrel-phy")) phy_register_fixup(&foo_board_with_broken_micrel_phy);
Oh yes, but now I have to do that for Linux, for $BSD, and for anything else I want to run on the device. I thought dt was meant to allow us to describe the hardware. If this is the case, let's just call this linuxtree and let everyone else get on with their own thing again. See also comment below.
If your machine compatible string does not allow you to uniquely identify your machine, this is a DT problem, as this should really be the case. If you do not want to add this code to wherever this is relevant in arch/arm/mach-shmobile/board-*.c, neither is drivers/net/phy/phy_device.c this the place to add it.
So where should it be added? If we keep piling stuff into board files in arch/arm.... then we're just back to the pre-dt case and going to keep getting shouted at.
Dealing with quirks applying to industry standard blocks is to update the relevant driver, based on information provided by the specifically affected systems. Failure to identify either of those correctly is a problem that must not lead to a generic "let's override PHY registers from DT" type of solution. As usual, mechanism vs policy applies even more when DT is involved.
There's an industry standard for the access method, but every PHY seems to have different extra setup registers for their own cases. I will leave this out here in case anyone else finds it useful, there may be a case where there are PHYs that need an amount of register initialisation and this code may be smaller than putting a pile of dt properties in. -- Ben Dooks http://www.codethink.co.uk/ Senior Engineer Codethink - Providing Genius -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
