Date:   Fri, 26 Feb 2021 11:19:56 +0100
From:   Daniel González Cabanelas <dgcbueu@...il.com>
To:     Heiner Kallweit <hkallweit1@...il.com>
Cc:     Andrew Lunn <andrew@...n.ch>,
        Florian Fainelli <f.fainelli@...il.com>,
        "David S. Miller" <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>, gregkh@...uxfoundation.org,
        netdev@...r.kernel.org,
        Álvaro Fernández Rojas <noltari@...il.com>
Subject: Re: [PATCH v2] bcm63xx_enet: fix internal phy IRQ assignment

El vie, 26 feb 2021 a las 11:08, Heiner Kallweit
(<hkallweit1@...il.com>) escribió:
>
> On 26.02.2021 10:49, Daniel González Cabanelas wrote:
> > El vie, 26 feb 2021 a las 10:32, Heiner Kallweit
> > (<hkallweit1@...il.com>) escribió:
> >>
> >> On 26.02.2021 10:10, Daniel González Cabanelas wrote:
> >>> El vie, 26 feb 2021 a las 8:13, Heiner Kallweit
> >>> (<hkallweit1@...il.com>) escribió:
> >>>>
> >>>> On 25.02.2021 23:28, Daniel González Cabanelas wrote:
> >>>>> El jue, 25 feb 2021 a las 21:05, Heiner Kallweit
> >>>>> (<hkallweit1@...il.com>) escribió:
> >>>>>>
> >>>>>> On 25.02.2021 17:36, Daniel González Cabanelas wrote:
> >>>>>>> El jue, 25 feb 2021 a las 8:22, Heiner Kallweit
> >>>>>>> (<hkallweit1@...il.com>) escribió:
> >>>>>>>>
> >>>>>>>> On 25.02.2021 00:54, Daniel González Cabanelas wrote:
> >>>>>>>>> El mié, 24 feb 2021 a las 23:01, Florian Fainelli
> >>>>>>>>> (<f.fainelli@...il.com>) escribió:
> >>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>>> On 2/24/2021 1:44 PM, Heiner Kallweit wrote:
> >>>>>>>>>>> On 24.02.2021 16:44, Daniel González Cabanelas wrote:
> >>>>>>>>>>>> The current bcm63xx_enet driver doesn't asign the internal phy IRQ. As a
> >>>>>>>>>>>> result of this it works in polling mode.
> >>>>>>>>>>>>
> >>>>>>>>>>>> Fix it using the phy_device structure to assign the platform IRQ.
> >>>>>>>>>>>>
> >>>>>>>>>>>> Tested under a BCM6348 board. Kernel dmesg before the patch:
> >>>>>>>>>>>>    Broadcom BCM63XX (1) bcm63xx_enet-0:01: attached PHY driver [Broadcom
> >>>>>>>>>>>>               BCM63XX (1)] (mii_bus:phy_addr=bcm63xx_enet-0:01, irq=POLL)
> >>>>>>>>>>>>
> >>>>>>>>>>>> After the patch:
> >>>>>>>>>>>>    Broadcom BCM63XX (1) bcm63xx_enet-0:01: attached PHY driver [Broadcom
> >>>>>>>>>>>>               BCM63XX (1)] (mii_bus:phy_addr=bcm63xx_enet-0:01, irq=17)
> >>>>>>>>>>>>
> >>>>>>>>>>>> Pluging and uplugging the ethernet cable now generates interrupts and the
> >>>>>>>>>>>> PHY goes up and down as expected.
> >>>>>>>>>>>>
> >>>>>>>>>>>> Signed-off-by: Daniel González Cabanelas <dgcbueu@...il.com>
> >>>>>>>>>>>> ---
> >>>>>>>>>>>> changes in V2:
> >>>>>>>>>>>>   - snippet moved after the mdiobus registration
> >>>>>>>>>>>>   - added missing brackets
> >>>>>>>>>>>>
> >>>>>>>>>>>>  drivers/net/ethernet/broadcom/bcm63xx_enet.c | 13 +++++++++++--
> >>>>>>>>>>>>  1 file changed, 11 insertions(+), 2 deletions(-)
> >>>>>>>>>>>>
> >>>>>>>>>>>> diff --git a/drivers/net/ethernet/broadcom/bcm63xx_enet.c b/drivers/net/ethernet/broadcom/bcm63xx_enet.c
> >>>>>>>>>>>> index fd876721316..dd218722560 100644
> >>>>>>>>>>>> --- a/drivers/net/ethernet/broadcom/bcm63xx_enet.c
> >>>>>>>>>>>> +++ b/drivers/net/ethernet/broadcom/bcm63xx_enet.c
> >>>>>>>>>>>> @@ -1818,10 +1818,19 @@ static int bcm_enet_probe(struct platform_device *pdev)
> >>>>>>>>>>>>               * if a slave is not present on hw */
> >>>>>>>>>>>>              bus->phy_mask = ~(1 << priv->phy_id);
> >>>>>>>>>>>>
> >>>>>>>>>>>> -            if (priv->has_phy_interrupt)
> >>>>>>>>>>>> +            ret = mdiobus_register(bus);
> >>>>>>>>>>>> +
> >>>>>>>>>>>> +            if (priv->has_phy_interrupt) {
> >>>>>>>>>>>> +                    phydev = mdiobus_get_phy(bus, priv->phy_id);
> >>>>>>>>>>>> +                    if (!phydev) {
> >>>>>>>>>>>> +                            dev_err(&dev->dev, "no PHY found\n");
> >>>>>>>>>>>> +                            goto out_unregister_mdio;
> >>>>>>>>>>>> +                    }
> >>>>>>>>>>>> +
> >>>>>>>>>>>>                      bus->irq[priv->phy_id] = priv->phy_interrupt;
> >>>>>>>>>>>> +                    phydev->irq = priv->phy_interrupt;
> >>>>>>>>>>>> +            }
> >>>>>>>>>>>>
> >>>>>>>>>>>> -            ret = mdiobus_register(bus);
> >>>>>>>>>>>
> >>>>>>>>>>> You shouldn't have to set phydev->irq, this is done by phy_device_create().
> >>>>>>>>>>> For this to work bus->irq[] needs to be set before calling mdiobus_register().
> >>>>>>>>>>
> >>>>>>>>>> Yes good point, and that is what the unchanged code does actually.
> >>>>>>>>>> Daniel, any idea why that is not working?
> >>>>>>>>>
> >>>>>>>>> Hi Florian, I don't know. bus->irq[] has no effect, only assigning the
> >>>>>>>>> IRQ through phydev->irq works.
> >>>>>>>>>
> >>>>>>>>> I can resend the patch  without the bus->irq[] line since it's
> >>>>>>>>> pointless in this scenario.
> >>>>>>>>>
> >>>>>>>>
> >>>>>>>> It's still an ugly workaround and a proper root cause analysis should be done
> >>>>>>>> first. I can only imagine that phydev->irq is overwritten in phy_probe()
> >>>>>>>> because phy_drv_supports_irq() is false. Can you please check whether
> >>>>>>>> phydev->irq is properly set in phy_device_create(), and if yes, whether
> >>>>>>>> it's reset to PHY_POLL in phy_probe()?.
> >>>>>>>>
> >>>>>>>
> >>>>>>> Hi Heiner, I added some kernel prints:
> >>>>>>>
> >>>>>>> [    2.712519] libphy: Fixed MDIO Bus: probed
> >>>>>>> [    2.721969] =======phy_device_create===========
> >>>>>>> [    2.726841] phy_device_create: dev->irq = 17
> >>>>>>> [    2.726841]
> >>>>>>> [    2.832620] =======phy_probe===========
> >>>>>>> [    2.836846] phy_probe: phydev->irq = 17
> >>>>>>> [    2.840950] phy_probe: phy_drv_supports_irq = 0, phy_interrupt_is_valid = 1
> >>>>>>> [    2.848267] phy_probe: phydev->irq = -1
> >>>>>>> [    2.848267]
> >>>>>>> [    2.854059] =======phy_probe===========
> >>>>>>> [    2.858174] phy_probe: phydev->irq = -1
> >>>>>>> [    2.862253] phy_probe: phydev->irq = -1
> >>>>>>> [    2.862253]
> >>>>>>> [    2.868121] libphy: bcm63xx_enet MII bus: probed
> >>>>>>> [    2.873320] Broadcom BCM63XX (1) bcm63xx_enet-0:01: attached PHY
> >>>>>>> driver [Broadcom BCM63XX (1)] (mii_bus:phy_addr=bcm63xx_enet-0:01,
> >>>>>>> irq=POLL)
> >>>>>>>
> >>>>>>> Currently using kernel 5.4.99. I still have no idea what's going on.
> >>>>>>>
> >>>>>> Thanks for debugging. This confirms my assumption that the interrupt
> >>>>>> is overwritten in phy_probe(). I'm just scratching my head how
> >>>>>> phy_drv_supports_irq() can return 0. In 5.4.99 it's defined as:
> >>>>>>
> >>>>>> static bool phy_drv_supports_irq(struct phy_driver *phydrv)
> >>>>>> {
> >>>>>>         return phydrv->config_intr && phydrv->ack_interrupt;
> >>>>>> }
> >>>>>>
> >>>>>> And that's the PHY driver:
> >>>>>>
> >>>>>> static struct phy_driver bcm63xx_driver[] = {
> >>>>>> {
> >>>>>>         .phy_id         = 0x00406000,
> >>>>>>         .phy_id_mask    = 0xfffffc00,
> >>>>>>         .name           = "Broadcom BCM63XX (1)",
> >>>>>>         /* PHY_BASIC_FEATURES */
> >>>>>>         .flags          = PHY_IS_INTERNAL,
> >>>>>>         .config_init    = bcm63xx_config_init,
> >>>>>>         .ack_interrupt  = bcm_phy_ack_intr,
> >>>>>>         .config_intr    = bcm63xx_config_intr,
> >>>>>> }
> >>>>>>
> >>>>>> So both callbacks are set. Can you extend your debugging and check
> >>>>>> in phy_drv_supports_irq() which of the callbacks is missing?
> >>>>>>
> >>>>>
> >>>>> Hi, both callbacks are missing on the first check. However on the next
> >>>>> calls they're there.
> >>>>>
> >>>>> [    2.263909] libphy: Fixed MDIO Bus: probed
> >>>>> [    2.273026] =======phy_device_create===========
> >>>>> [    2.277908] phy_device_create: dev->irq = 17
> >>>>> [    2.277908]
> >>>>> [    2.373104] =======phy_probe===========
> >>>>> [    2.377336] phy_probe: phydev->irq = 17
> >>>>> [    2.381445] phy_drv_supports_irq: phydrv->config_intr = 0,
> >>>>> phydrv->ack_interrupt = 0
> >>>>> [    2.389554] phydev->irq = PHY_POLL;
> >>>>> [    2.393186] phy_probe: phydev->irq = -1
> >>>>> [    2.393186]
> >>>>> [    2.398987] =======phy_probe===========
> >>>>> [    2.403108] phy_probe: phydev->irq = -1
> >>>>> [    2.407195] phy_drv_supports_irq: phydrv->config_intr = 1,
> >>>>> phydrv->ack_interrupt = 1
> >>>>> [    2.415314] phy_probe: phydev->irq = -1
> >>>>> [    2.415314]
> >>>>> [    2.421189] libphy: bcm63xx_enet MII bus: probed
> >>>>> [    2.426129] =======phy_connect===========
> >>>>> [    2.430410] phy_drv_supports_irq: phydrv->config_intr = 1,
> >>>>> phydrv->ack_interrupt = 1
> >>>>> [    2.438537] phy_connect: phy_drv_supports_irq = 1
> >>>>> [    2.438537]
> >>>>> [    2.445284] Broadcom BCM63XX (1) bcm63xx_enet-0:01: attached PHY
> >>>>> driver [Broadcom BCM63XX (1)] (mii_bus:phy_addr=bcm63xx_enet-0:01,
> >>>>> irq=POLL)
> >>>>>
> >>>>
> >>>> I'd like to understand why the phy_device is probed twice,
> >>>> with which drivers it's probed.
> >>>> Could you please add printing phydrv->name to phy_probe() ?
> >>>>
> >>>
> >>> Hi Heiner, indeed there are two different probed devices. The B53
> >>> switch driver is causing this issue.
> >>>
> >>> [    2.269595] libphy: Fixed MDIO Bus: probed
> >>> [    2.278706] =======phy_device_create===========
> >>> [    2.283594] phy_device_create: dev->irq = 17
> >>> [    2.283594]
> >>> [    2.379554] =======phy_probe===========
> >>> [    2.383780] phy_probe: phydrv->name = Broadcom B53 (3)
> >>
> >> Is this an out-of-tree driver? I can't find this string in any
> >> DSA or PHY driver.
> >>
> >
> > Yes it is.
> > https://github.com/openwrt/openwrt/blob/master/target/linux/generic/files/drivers/net/phy/b53/b53_mdio.c#L421
> >
>
> OK, I see. Then there's no reason to complain upstream.
> Either use the mainline B53 DSA driver of fix interrupt mode
> downstream.

I agree.

This b53 driver has one PHY with the same BCM63XX phy_id, causing a
double probe. I'll send the original patch to the OpenWrt project.

Thank you very much.
Daniel
>
> >>
> >>> [    2.389235] phy_probe: phydev->irq = 17
> >>> [    2.393332] phy_drv_supports_irq: phydrv->config_intr = 0,
> >>> phydrv->ack_interrupt = 0
> >>> [    2.401445] phydev->irq = PHY_POLL
> >>> [    2.405080] phy_probe: phydev->irq = -1
> >>> [    2.405080]
> >>> [    2.410878] =======phy_probe===========
> >>> [    2.414996] phy_probe: phydrv->name = Broadcom BCM63XX (1)
> >>> [    2.420791] phy_probe: phydev->irq = -1
> >>> [    2.424876] phy_drv_supports_irq: phydrv->config_intr = 1,
> >>> phydrv->ack_interrupt = 1
> >>> [    2.432994] phy_probe: phydev->irq = -1
> >>> [    2.432994]
> >>> [    2.438862] libphy: bcm63xx_enet MII bus: probed
> >>> [    2.443809] =======phy_connect===========
> >>> [    2.448092] phy_drv_supports_irq: phydrv->config_intr = 1,
> >>> phydrv->ack_interrupt = 1
> >>> [    2.456215] phy_connect: phy_drv_supports_irq = 1
> >>> [    2.456215]
> >>> [    2.462961] Broadcom BCM63XX (1) bcm63xx_enet-0:01: attached PHY
> >>> driver [Broadcom BCM63XX (1)] (mii_bus:phy_addr=bcm63xx_enet-0:01,
> >>> irq=POLL)
> >>>
> >>> The board has no switch, it's a driver for other boards in OpenWrt. I
> >>> forgot it wasn't upstreamed:
> >>> https://github.com/openwrt/openwrt/tree/master/target/linux/generic/files/drivers/net/phy/b53
> >>>
> >>> I tested a kernel compiled without this driver, now the IRQ is
> >>> detected as it should be:
> >>>
> >>> [    2.270707] libphy: Fixed MDIO Bus: probed
> >>> [    2.279715] =======phy_device_create===========
> >>> [    2.284600] phy_device_create: dev->irq = 17
> >>> [    2.284600]
> >>> [    2.373763] =======phy_probe===========
> >>> [    2.377989] phy_probe: phydrv->name = Broadcom BCM63XX (1)
> >>> [    2.383803] phy_probe: phydev->irq = 17
> >>> [    2.387888] phy_drv_supports_irq: phydrv->config_intr = 1,
> >>> phydrv->ack_interrupt = 1
> >>> [    2.396007] phy_probe: phydev->irq = 17
> >>> [    2.396007]
> >>> [    2.401877] libphy: bcm63xx_enet MII bus: probed
> >>> [    2.406820] =======phy_connect===========
> >>> [    2.411099] phy_drv_supports_irq: phydrv->config_intr = 1,
> >>> phydrv->ack_interrupt = 1
> >>> [    2.419226] phy_connect: phy_drv_supports_irq = 1
> >>> [    2.419226]
> >>> [    2.429857] Broadcom BCM63XX (1) bcm63xx_enet-0:01: attached PHY
> >>> driver [Broadcom BCM63XX (1)] (mii_bus:phy_addr=bcm63xx_enet-0:01,
> >>> irq=17)
> >>>
> >>> Then, maybe this is an OpenWrt bug itself?
> >>>
> >>> Regards
> >>> Daniel
> >>>
> >>>>
> >>>>> I also added the prints to phy_connect.
> >>>>>
> >>>>>> Last but not least: Do you use a mainline kernel, or is it maybe
> >>>>>> a modified downstream kernel? In the latter case, please check
> >>>>>> in your kernel sources whether both callbacks are set.
> >>>>>>
> >>>>>
> >>>>> It's a modified kernel, and the the callbacks are set. BTW I also
> >>>>> tested the kernel with no patches concerning to the ethernet driver.
> >>>>>
> >>>>> Regards,
> >>>>> Daniel
> >>>>>
> >>>>>>
> >>>>>>
> >>>>>>>> On which kernel version do you face this problem?
> >>>>>>>>
> >>>>>>> The kernel version 4.4 works ok. The minimum version where I found the
> >>>>>>> problem were the kernel 4.9.111, now using 5.4. And 5.10 also tested.
> >>>>>>>
> >>>>>>> Regards
> >>>>>>> Daniel
> >>>>>>>
> >>>>>>>>> Regards
> >>>>>>>>>> --
> >>>>>>>>>> Florian
> >>>>>>>>
> >>>>>>
> >>>>
> >>
>

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