[OpenWrt-Devel] Autoneg problems with ar8216 on kernel 3.14 (related to ticket 17800)
Weedy
weedy2887 at gmail.com
Sun Nov 23 16:35:50 EST 2014
On Nov 19, 2014 8:47 AM, "John Crispin" <blogic at openwrt.org> wrote:
>
>
>
> On 19/11/2014 14:44, Weedy wrote:
> >
> > On Oct 30, 2014 5:08 PM, "Heiner Kallweit" <hkallweit1 at gmail.com
> > <mailto:hkallweit1 at gmail.com>> wrote:
> >>
> >> Am 30.10.2014 um 07:22 schrieb Heiner Kallweit:
> >> > Am 30.10.2014 um 03:36 schrieb Florian Fainelli:
> >> >> Le 28/10/2014 11:46, Heiner Kallweit a écrit :
> >> >>> After a little more thinking about it and looking at the code I
> > basically have two questions:
> >> >>>
> >> >>> 1.
> >> >>> Is it actually needed to exclude certain phy's in
> > ar8xxx_phy_config_aneg?
> >> >>> (At least for AR8327 it doesn't get called with an addr != 0
anyway)
> >> >>> Else we could remove ar8xxx_phy_config_aneg and directly register
> > genphy_config_aneg as
> >> >>> callback for autoneg configuration.
> >> >>
> >> >> Address 0 is special, since this is a MDIO broadcast address that
> > will usually be handled by switches as "write to all front-panel ports".
> >> >>
> >> >>>
> >> >>> 2.
> >> >>> Call sequence with regard to ar8216 is:
> >> >>> ar8216: ar8xxx_phy_probe
> >> >>> phy: phy_attach_direct
> >> >>> phy: phy_init_hw
> >> >>> ar8216: ar8xxx_phy_config_init
> >> >>> ar8216: ar8xxx_phy_config_aneg
> >> >>>
> >> >>> ar8216 driver handles AR8327/AR8337 different from the other
> > supported switch types.
> >> >>> ar8xxx_start incl. more detailed configuration is called from
> > ar8xxx_phy_probe already.
> >> >>> For the other switch types it's called from ar8xxx_phy_config_init.
> >> >>>
> >> >>> I wonder whether doing detailed configuration in the probe stage
> > might be too early.
> >> >>> phy_init_hw resets the switch anyway later.
> >> >>> Doing the detailed setup in ar8xxx_phy_config_init seems to be
> > more suited however
> >> >>> there might be good reason why it's handled the way it is.
> >> >>
> >> >> I suppose that you could re-advertise auto-negotiation by calling
> > genphy_config_advert() in the config_init routine.
> >> >
> >> > The actual problem is caused by BMCR_ANENABLE being cleared by the
> > reset in phy_init_hw.
> >> > As far as I can see genphy_config_advert doesn't bring back this
flag.
> >> > What does genphy_config_aneg mainly do?
> >> > - call genphy_config_advert
> >> > - check if BMCR_ANENABLE is set
> >> > - if it's not, call genphy_restart_aneg
> >> > Therefore, to bring back BMCR_ANENABLE, we have to call
> > genphy_config_aneg or genphy_restart_aneg.
> >> > genphy_restart_aneg most likely is sufficient, however I don't see
> > that genphy_config_aneg
> >> > can do any harm if being called with addr == 0.
> >> > At least for me it works perfectly fine to call genphy_config_aneg
> > for all addr's.
> >> >
> >> > Rgds, Heiner
> >> >
> >> >>
> >> >>>
> >> >>> Rgds,
> >> >>> Heiner
> >> >>>
> >> >>>
> >> >>> Am 27.10.2014 um 22:00 schrieb Heiner Kallweit:
> >> >>>> With two different TPLINK routers (both with a AR8327N switch) I
> > faced the issue that with
> >> >>>> kernel 3.14 certain switch ports used 10MBit/half only.
> >> >>>> Under kernel 3.10 everything was fine and the same ports used
> > 1000MBit/full.
> >> >>>>
> >> >>>> As the ar8216 driver is the same I had a look at the common phy
> > code in drivers/net/phy.
> >> >>>> In function phy_init_hw in phy_device.c kernel 3.14 resets the
> > phy whilst 3.10 does not.
> >> >>>>
> >> >>>> The issue turned out to be that when resetting only flag
> > BMCR_RESET is set, not BMCR_ANENABLE.
> >> >>>> (In ar8216.c always both flags are set when the switch is reset)
> >> >>>> Therefore autoneg was not enabled. Also later in the boot process
> > it doesn't get enabled.
> >> >>>> Adding BMCR_ANENABLE solved the problem and now also under 3.14
> > all ports use 1000MBit/full.
> >> >>>>
> >> >>>> However I'm not sure whether it's a poper fix to add
> > BMCR_ANENABLE in this generic phy function.
> >> >>>> It might not be appropriate for other phy's.
> >> >>>>
> >> >>>> After resetting the switch later in the boot process
> > ar8xxx_phy_config_aneg is called with
> >> >>>> phydev->addr being 0.
> >> >>>> In this case the function returns immediately. Otherwise it would
> > call genphy_config_aneg.
> >> >>>> Calling genphy_config_aneg would also solve the problem as it
> > checks for BMCR_ANENABLE
> >> >>>> being set and sets it if needed.
> >> >>>> I don't know the reason why genphy_config_aneg isn't called in
> > case of addr 0.
> >> >>>> Or is this a typo and the check actually should be addr != 0 ?
> >> >>>>
> >> >>>> Rgds, Heiner
> >> >>>>
> >>
> >> The following rudimentary patch works fine for me with kernel 3.14.18
on
> >> TP-LINK TL-WDR4900 (mpc85xx with AR8327Nv4)
> >> TP-LINK TL-WDR4300 ( ar71xx with AR8327Nv2)
> >>
> >> Apart from using genphy_config_aneg also for addr==0 I replaced
> > msleep(1000)
> >> with a polling function inspired by phy_poll_reset in phy_device.c
> >> On AR8327 the reset actually takes less than 20ms. Sleeping for 1000ms
> >> seems to be a waste of time.
> >>
> >> Little more work would be needed to make it a proper patch:
> >> - move ar8xxx_phy_poll_reset more to the beginning so that it is
defined
> >> before being used in any xxxx_hw_init function
> >> - replace msleep(1000) also in the other xxxx_hw_init functions
> >> - remove pr_info debug message or make it at least pr_dbg
> >> - insert some comments
> >> - use git format-patch output
> >>
> >> Rgds, Heiner
> >>
> >>
> >> --- ar8216.c.orig 2014-10-30 21:50:19.999723156 +0100
> >> +++ ar8216.c 2014-10-30 21:42:11.996481099 +0100
> >> @@ -1591,6 +1591,29 @@
> >> #endif
> >>
> >> static int
> >> +ar8xxx_phy_poll_reset(struct mii_bus *bus, int num_phys)
> >> +{
> >> + unsigned int sleep_msecs = 20;
> >> + int ret, elapsed, i;
> >> +
> >> + for(elapsed = sleep_msecs; elapsed <= 600; elapsed +=
> > sleep_msecs) {
> >> + msleep(sleep_msecs);
> >> + for (i = 0; i < num_phys; i++) {
> >> + ret = mdiobus_read(bus, i, MII_BMCR);
> >> + if (ret < 0) return ret;
> >> + if (ret & BMCR_RESET) break;
> >> + if (i == num_phys - 1) {
> >> + usleep_range(1000, 2000);
> >> + pr_info("ar8xxx_phy_poll_reset
> > finished in %u ms\n",
> >> + elapsed);
> >> + return 0;
> >> + }
> >> + }
> >> + }
> >> + return -ETIMEDOUT;
> >> +}
> >> +
> >> +static int
> >> ar8327_hw_init(struct ar8xxx_priv *priv)
> >> {
> >> struct mii_bus *bus;
> >> @@ -1620,7 +1643,7 @@
> >> mdiobus_write(bus, i, MII_BMCR, BMCR_RESET |
> > BMCR_ANENABLE);
> >> }
> >>
> >> - msleep(1000);
> >> + ar8xxx_phy_poll_reset(bus, AR8327_NUM_PHYS);
> >>
> >> return 0;
> >> }
> >> @@ -2840,15 +2863,6 @@
> >> return ret;
> >> }
> >>
> >> -static int
> >> -ar8xxx_phy_config_aneg(struct phy_device *phydev)
> >> -{
> >> - if (phydev->addr == 0)
> >> - return 0;
> >> -
> >> - return genphy_config_aneg(phydev);
> >> -}
> >> -
> >> static const u32 ar8xxx_phy_ids[] = {
> >> 0x004dd033,
> >> 0x004dd034, /* AR8327 */
> >> @@ -3020,7 +3034,7 @@
> >> .remove = ar8xxx_phy_remove,
> >> .detach = ar8xxx_phy_detach,
> >> .config_init = ar8xxx_phy_config_init,
> >> - .config_aneg = ar8xxx_phy_config_aneg,
> >> + .config_aneg = genphy_config_aneg,
> >> .read_status = ar8xxx_phy_read_status,
> >> .driver = { .owner = THIS_MODULE },
> >> };
> >> _______________________________________________
> >> openwrt-devel mailing list
> >> openwrt-devel at lists.openwrt.org <mailto:openwrt-devel at lists.openwrt.org
>
> >> https://lists.openwrt.org/cgi-bin/mailman/listinfo/openwrt-devel
> >
> > I feel like this shouldn't die off in the depths of the ML
> >
>
> we had a call about it today, this patch and the other ar821x patches
> will be handled soon
You guys bumped trunk to 3.14 but didn't fix this.
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