On 16/11/15 12:05, Adrian Chadd wrote: > On 16 November 2015 at 11:48, Florian Fainelli <f.faine...@gmail.com> wrote: >> On 16/11/15 11:29, Adrian Chadd wrote: >>> hi, >>> >>> I'm debugging an issue on the Broadcom parts (using unimac-mdio.c as >>> the mdio bus) where i occasionally see MDIO bus read failures, which >>> causes phy.c to transition the PHY to PHY_HALTED. It stays in this >>> state until the link is bounced. >> >> There is a known problem with some Broadcom PHYs where the first MDIO >> read may fail, and this can actually show up randomly in time, not just >> the first read and that caused the PHY library to enter PHY_HALTED. >> Which part are you seeing this? unimac-mdio.c has a reset hook just for >> that cases. > > It's the broadcom BCM7444. > > The failure is -EIO from the unimac-mdio read method, which only > happens when the hardware returns MDIO_READ_FAIL. > >>> So, what's the expectation to handle this and recover from it? is >>> there some userland piece monitoring things that I'm missing? >> >> There is not much you can do typically, but ignore or retry the read, or >> workaround it if you can, like what bcm7xxx.c does. > > What's the reset hack in bcm7xxx.c ? I don't see anything obvious.
That part: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/net/phy/bcm7xxx.c#n175 > > (I'm currently stuck on 3.14.13-1.2 from broadcom's stb tree.) That would explain it, the workaround mentioned above only made it in 3.14-1.8, and there are more releases available to you now, we should probably talk off line about this downstream kernel. -- Florian -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
