Messages in this thread | | | From | Geert Uytterhoeven <> | Date | Thu, 18 May 2017 22:36:13 +0200 | Subject | Re: [PATCH] of_mdio: Fix broken PHY IRQ in case of probe deferral |
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Hi Andrew,
On Thu, May 18, 2017 at 9:34 PM, Andrew Lunn <andrew@lunn.ch> wrote: >> > This most certainly works fine in the simple case where you have one PHY >> > hanging off the MDIO bus, now what happens if you have several? >> > >> > Presumably, the first PHY that returns EPROBE_DEFER will make the entire >> > bus registration return EPROB_DEFER as well, and so on, and so forth, >> > but I am not sure if we will be properly unwinding the successful >> > registration of PHYs that either don't have an interrupt, or did not >> > return EPROBE_DEFER. >> > >> > It should be possible to mimic this behavior by using the fixed PHY, and >> > possibly the dsa_loop.c driver which would create 4 ports, expecting 4 >> > fixed PHYs to be present. >> >> mdiobus_unregister(), called from of_mdiobus_register() on failure, >> should do the unwinding, right? >> >> And when the driver is reprobed, all PHYs are reprobed, until they all >> succeed. > > That is the theory. I looked at that while reviewing the patch. But > this has probably not been tested in anger. It would be good to test > this properly, with not just the first PHY returning -EPROBE_DEFER, to > really test the unwind.
Unfortunately I don't have a board with multiple PHYs, so I cannot test that case.
Does unbinding/rebinding a network driver with multiple PHYs currently work? Or module unload/reload?
That should exercise a similar code path.
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
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