diff mbox series

[v2,3/9] net: mdio: Delete usage of driver_deferred_probe_check_state()

Message ID 20220601070707.3946847-4-saravanak@google.com
State Superseded
Headers show
Series deferred_probe_timeout logic clean up | expand

Commit Message

Saravana Kannan June 1, 2022, 7:06 a.m. UTC 
Now that fw_devlink=on by default and fw_devlink supports interrupt
properties, the execution will never get to the point where
driver_deferred_probe_check_state() is called before the supplier has
probed successfully or before deferred probe timeout has expired.

So, delete the call and replace it with -ENODEV.

Signed-off-by: Saravana Kannan <saravanak@google.com>
---
 drivers/net/mdio/fwnode_mdio.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

Comments

Geert Uytterhoeven July 5, 2022, 9:11 a.m. UTC | #1 
Hi Saravana,

On Wed, Jun 1, 2022 at 2:44 PM Saravana Kannan <saravanak@google.com> wrote:
> Now that fw_devlink=on by default and fw_devlink supports interrupt
> properties, the execution will never get to the point where
> driver_deferred_probe_check_state() is called before the supplier has
> probed successfully or before deferred probe timeout has expired.
>
> So, delete the call and replace it with -ENODEV.
>
> Signed-off-by: Saravana Kannan <saravanak@google.com>

Thanks for your patch, which is now commit f8217275b57aa48d ("net:
mdio: Delete usage of driver_deferred_probe_check_state()") in
driver-core/driver-core-next.

Seems like I missed something when providing my T-b for this series,
sorry for that.

arch/arm/boot/dts/r8a7791-koelsch.dts has:

    &ether {
            pinctrl-0 = <&ether_pins>, <&phy1_pins>;
            pinctrl-names = "default";

            phy-handle = <&phy1>;
            renesas,ether-link-active-low;
            status = "okay";

            phy1: ethernet-phy@1 {
                    compatible = "ethernet-phy-id0022.1537",
                                 "ethernet-phy-ieee802.3-c22";
                    reg = <1>;
                    interrupt-parent = <&irqc0>;
                    interrupts = <0 IRQ_TYPE_LEVEL_LOW>;
                    micrel,led-mode = <1>;
                    reset-gpios = <&gpio5 22 GPIO_ACTIVE_LOW>;
            };
    };

Despite the interrupts property, &ether is now probed before irqc0
(interrupt-controller@e61c0000 in arch/arm/boot/dts/r8a7791.dtsi),
causing the PHY not finding its interrupt, and resorting to polling:

    -Micrel KSZ8041RNLI ee700000.ethernet-ffffffff:01: attached PHY
driver (mii_bus:phy_addr=ee700000.ethernet-ffffffff:01, irq=185)
    +Micrel KSZ8041RNLI ee700000.ethernet-ffffffff:01: attached PHY
driver (mii_bus:phy_addr=ee700000.ethernet-ffffffff:01, irq=POLL)

Reverting this commit, and commit 9cbffc7a59561be9 ("driver core:
Delete driver_deferred_probe_check_state()") fixes that.

> --- a/drivers/net/mdio/fwnode_mdio.c
> +++ b/drivers/net/mdio/fwnode_mdio.c
> @@ -47,9 +47,7 @@ int fwnode_mdiobus_phy_device_register(struct mii_bus *mdio,
>          * just fall back to poll mode
>          */
>         if (rc == -EPROBE_DEFER)
> -               rc = driver_deferred_probe_check_state(&phy->mdio.dev);
> -       if (rc == -EPROBE_DEFER)
> -               return rc;
> +               rc = -ENODEV;
>
>         if (rc > 0) {
>                 phy->irq = rc;

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
Saravana Kannan July 13, 2022, 1:40 a.m. UTC | #2 
On Tue, Jul 5, 2022 at 2:11 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>
> Hi Saravana,
>
> On Wed, Jun 1, 2022 at 2:44 PM Saravana Kannan <saravanak@google.com> wrote:
> > Now that fw_devlink=on by default and fw_devlink supports interrupt
> > properties, the execution will never get to the point where
> > driver_deferred_probe_check_state() is called before the supplier has
> > probed successfully or before deferred probe timeout has expired.
> >
> > So, delete the call and replace it with -ENODEV.
> >
> > Signed-off-by: Saravana Kannan <saravanak@google.com>
>
> Thanks for your patch, which is now commit f8217275b57aa48d ("net:
> mdio: Delete usage of driver_deferred_probe_check_state()") in
> driver-core/driver-core-next.
>
> Seems like I missed something when providing my T-b for this series,
> sorry for that.

No worries. Appreciate any testing help.

>
> arch/arm/boot/dts/r8a7791-koelsch.dts has:
>
>     &ether {
>             pinctrl-0 = <&ether_pins>, <&phy1_pins>;
>             pinctrl-names = "default";
>
>             phy-handle = <&phy1>;
>             renesas,ether-link-active-low;
>             status = "okay";
>
>             phy1: ethernet-phy@1 {
>                     compatible = "ethernet-phy-id0022.1537",
>                                  "ethernet-phy-ieee802.3-c22";
>                     reg = <1>;
>                     interrupt-parent = <&irqc0>;
>                     interrupts = <0 IRQ_TYPE_LEVEL_LOW>;
>                     micrel,led-mode = <1>;
>                     reset-gpios = <&gpio5 22 GPIO_ACTIVE_LOW>;
>             };
>     };
>
> Despite the interrupts property, &ether is now probed before irqc0
> (interrupt-controller@e61c0000 in arch/arm/boot/dts/r8a7791.dtsi),
> causing the PHY not finding its interrupt, and resorting to polling:

I'd still expect the device link to have been created properly for
this phy device. Could you enable the logging in device_link_add() to
check the link is created between the phy and the IRQ?

My guess is that this probably has something to do with phys being
attached to drivers differently.

>
>     -Micrel KSZ8041RNLI ee700000.ethernet-ffffffff:01: attached PHY
> driver (mii_bus:phy_addr=ee700000.ethernet-ffffffff:01, irq=185)
>     +Micrel KSZ8041RNLI ee700000.ethernet-ffffffff:01: attached PHY
> driver (mii_bus:phy_addr=ee700000.ethernet-ffffffff:01, irq=POLL)

Can you drop a WARN() where this is printed to get the stack trace to
check my hypothesis?

-Saravana

>
> Reverting this commit, and commit 9cbffc7a59561be9 ("driver core:
> Delete driver_deferred_probe_check_state()") fixes that.
>
> > --- a/drivers/net/mdio/fwnode_mdio.c
> > +++ b/drivers/net/mdio/fwnode_mdio.c
> > @@ -47,9 +47,7 @@ int fwnode_mdiobus_phy_device_register(struct mii_bus *mdio,
> >          * just fall back to poll mode
> >          */
> >         if (rc == -EPROBE_DEFER)
> > -               rc = driver_deferred_probe_check_state(&phy->mdio.dev);
> > -       if (rc == -EPROBE_DEFER)
> > -               return rc;
> > +               rc = -ENODEV;
> >
> >         if (rc > 0) {
> >                 phy->irq = rc;
>
> 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
Geert Uytterhoeven July 13, 2022, 11:39 a.m. UTC | #3 
Hi Saravana,

On Wed, Jul 13, 2022 at 3:40 AM Saravana Kannan <saravanak@google.com> wrote:
> On Tue, Jul 5, 2022 at 2:11 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> > On Wed, Jun 1, 2022 at 2:44 PM Saravana Kannan <saravanak@google.com> wrote:
> > > Now that fw_devlink=on by default and fw_devlink supports interrupt
> > > properties, the execution will never get to the point where
> > > driver_deferred_probe_check_state() is called before the supplier has
> > > probed successfully or before deferred probe timeout has expired.
> > >
> > > So, delete the call and replace it with -ENODEV.
> > >
> > > Signed-off-by: Saravana Kannan <saravanak@google.com>
> >
> > Thanks for your patch, which is now commit f8217275b57aa48d ("net:
> > mdio: Delete usage of driver_deferred_probe_check_state()") in
> > driver-core/driver-core-next.
> >
> > Seems like I missed something when providing my T-b for this series,
> > sorry for that.
>
> > arch/arm/boot/dts/r8a7791-koelsch.dts has:
> >
> >     &ether {
> >             pinctrl-0 = <&ether_pins>, <&phy1_pins>;
> >             pinctrl-names = "default";
> >
> >             phy-handle = <&phy1>;
> >             renesas,ether-link-active-low;
> >             status = "okay";
> >
> >             phy1: ethernet-phy@1 {
> >                     compatible = "ethernet-phy-id0022.1537",
> >                                  "ethernet-phy-ieee802.3-c22";
> >                     reg = <1>;
> >                     interrupt-parent = <&irqc0>;
> >                     interrupts = <0 IRQ_TYPE_LEVEL_LOW>;
> >                     micrel,led-mode = <1>;
> >                     reset-gpios = <&gpio5 22 GPIO_ACTIVE_LOW>;
> >             };
> >     };
> >
> > Despite the interrupts property, &ether is now probed before irqc0
> > (interrupt-controller@e61c0000 in arch/arm/boot/dts/r8a7791.dtsi),
> > causing the PHY not finding its interrupt, and resorting to polling:
>
> I'd still expect the device link to have been created properly for
> this phy device. Could you enable the logging in device_link_add() to
> check the link is created between the phy and the IRQ?
>
> My guess is that this probably has something to do with phys being
> attached to drivers differently.

Comparison of dmesg before/after enabling debugging, for
related nodes:

    +interrupt-controller@e61c0000 Linked as a fwnode consumer to
clock-controller@e6150000

    +pmic@58 Linked as a fwnode consumer to interrupt-controller@e61c0000
    +regulator@68 Linked as a fwnode consumer to interrupt-controller@e61c0000

Other user of irqc

    +ethernet@ee700000 Linked as a fwnode consumer to clock-controller@e6150000
    +ethernet@ee700000 Linked as a fwnode consumer to pinctrl@e6060000
    +ethernet-phy@1 Linked as a fwnode consumer to interrupt-controller@e61c0000
    +ethernet-phy@1 Linked as a fwnode consumer to gpio@e6055000

PHY linked correctly to consumers

    +device: 'e61c0000.interrupt-controller': device_add
    +device: 'platform:e6150000.clock-controller--platform:e61c0000.interrupt-controller':
device_add
    +devices_kset: Moving e61c0000.interrupt-controller to end of list
    +platform e61c0000.interrupt-controller: Linked as a consumer to
e6150000.clock-controller
    +interrupt-controller@e61c0000 Dropping the fwnode link to
clock-controller@e6150000
    +platform e61c0000.interrupt-controller: error -EPROBE_DEFER:
supplier e6150000.clock-controller not ready

Tried to probe irqc (why? consumer not ready), deferred.

    +device: 'platform:e61c0000.interrupt-controller--platform:e60b0000.i2c':
device_add
    +platform e60b0000.i2c: Linked as a sync state only consumer to
e61c0000.interrupt-controller

I guess sync state means through other (child) consumers (pmic,
regulator) above?

    +device: 'ee700000.ethernet': device_add
    +device: 'platform:e6060000.pinctrl--platform:ee700000.ethernet': device_add
    +devices_kset: Moving ee700000.ethernet to end of list
    +platform ee700000.ethernet: Linked as a consumer to e6060000.pinctrl
    +ethernet@ee700000 Dropping the fwnode link to pinctrl@e6060000
    +device: 'platform:e6150000.clock-controller--platform:ee700000.ethernet':
device_add
    +devices_kset: Moving ee700000.ethernet to end of list
    +platform ee700000.ethernet: Linked as a consumer to
e6150000.clock-controller
    +ethernet@ee700000 Dropping the fwnode link to clock-controller@e6150000
    +device: 'platform:e6055000.gpio--platform:ee700000.ethernet': device_add
    +platform ee700000.ethernet: Linked as a sync state only consumer
to e6055000.gpio
    +device: 'platform:e61c0000.interrupt-controller--platform:ee700000.ethernet':
device_add
    +platform ee700000.ethernet: Linked as a sync state only consumer
to e61c0000.interrupt-controller

Hence linking ethernet to child (phy) consumers.

    +device: 'ee700000.ethernet-ffffffff': device_add

Probing ethernet...

     libphy: fwnode_get_phy_id: fwnode
/soc/ethernet@ee700000/ethernet-phy@1 phy_id = 0x00221537
     libphy: fwnode_get_phy_id: fwnode
/soc/ethernet@ee700000/ethernet-phy@1 phy_id = 0x00221537
    +fwnode_mdiobus_phy_device_register: fwnode_irq_get() returned -517
    +fwnode_mdiobus_phy_device_register: ignoring -EPROBE_DEFER

This is the part that got changed by this patch.

    +device: 'ee700000.ethernet-ffffffff:01': device_add
    +device: 'platform:e6055000.gpio--mdio_bus:ee700000.ethernet-ffffffff:01':
device_add
    +devices_kset: Moving ee700000.ethernet-ffffffff:01 to end of list
    +mdio_bus ee700000.ethernet-ffffffff:01: Linked as a consumer to
e6055000.gpio
    +ethernet-phy@1 Dropping the fwnode link to gpio@e6055000
    +device: 'platform:e61c0000.interrupt-controller--mdio_bus:ee700000.ethernet-ffffffff:01':
device_add
    +devices_kset: Moving ee700000.ethernet-ffffffff:01 to end of list
    +mdio_bus ee700000.ethernet-ffffffff:01: Linked as a consumer to
e61c0000.interrupt-controller
    +ethernet-phy@1 Dropping the fwnode link to interrupt-controller@e61c0000
    +mdio_bus ee700000.ethernet-ffffffff:01: error -EPROBE_DEFER:
supplier e61c0000.interrupt-controller not ready

Why was ethernet probed this early?
We knew the supplier of the phy was still missing?

    +device: 'eth1': device_add
     sh-eth ee700000.ethernet eth1: Base address at 0xee700000,
2e:09:0a:00:6d:85, IRQ 104.
    +sh-eth ee700000.ethernet: Dropping the link to e6055000.gpio
    +device: 'platform:e6055000.gpio--platform:ee700000.ethernet':
device_unregister
    +sh-eth ee700000.ethernet: Dropping the link to
e61c0000.interrupt-controller
    +device: 'platform:e61c0000.interrupt-controller--platform:ee700000.ethernet':
device_unregister

    +devices_kset: Moving e61c0000.interrupt-controller to end of list
    +devices_kset: Moving ee700000.ethernet-ffffffff:01 to end of list
     renesas_irqc e61c0000.interrupt-controller: driving 10 irqs

Finally, irqc is probed.

    +device: '6-0058': device_add
    +device: 'platform:e61c0000.interrupt-controller--i2c:6-0058': device_add
    +devices_kset: Moving 6-0058 to end of list
    +i2c 6-0058: Linked as a consumer to e61c0000.interrupt-controller
    +pmic@58 Dropping the fwnode link to interrupt-controller@e61c0000

    +device: '6-0068': device_add
    +device: 'platform:e61c0000.interrupt-controller--i2c:6-0068': device_add
    +devices_kset: Moving 6-0068 to end of list
    +i2c 6-0068: Linked as a consumer to e61c0000.interrupt-controller
    +regulator@68 Dropping the fwnode link to interrupt-controller@e61c0000

Propagating other irqc suppliers to the parent of their consumers

    +i2c-sh_mobile e60b0000.i2c: Dropping the link to
e61c0000.interrupt-controller
    +device: 'platform:e61c0000.interrupt-controller--platform:e60b0000.i2c':
device_unregister

    +devices_kset: Moving ee700000.ethernet-ffffffff:01 to end of list

     Micrel KSZ8041RNLI ee700000.ethernet-ffffffff:01: attached PHY
driver (mii_bus:phy_addr=ee700000.ethernet-ffffffff:01, irq=POLL)
     sh-eth ee700000.ethernet eth1: Link is Up - 100Mbps/Full - flow control off
     Sending DHCP requests ., OK

> >     -Micrel KSZ8041RNLI ee700000.ethernet-ffffffff:01: attached PHY
> > driver (mii_bus:phy_addr=ee700000.ethernet-ffffffff:01, irq=185)
> >     +Micrel KSZ8041RNLI ee700000.ethernet-ffffffff:01: attached PHY
> > driver (mii_bus:phy_addr=ee700000.ethernet-ffffffff:01, irq=POLL)
>
> Can you drop a WARN() where this is printed to get the stack trace to
> check my hypothesis?

That didn't help much, as this is the messenger, not the cause.

Thanks!

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
Geert Uytterhoeven Aug. 15, 2022, 8:38 a.m. UTC | #4 
Hi Saravana,

On Tue, Jul 5, 2022 at 11:11 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> On Wed, Jun 1, 2022 at 2:44 PM Saravana Kannan <saravanak@google.com> wrote:
> > Now that fw_devlink=on by default and fw_devlink supports interrupt
> > properties, the execution will never get to the point where
> > driver_deferred_probe_check_state() is called before the supplier has
> > probed successfully or before deferred probe timeout has expired.
> >
> > So, delete the call and replace it with -ENODEV.
> >
> > Signed-off-by: Saravana Kannan <saravanak@google.com>
>
> Thanks for your patch, which is now commit f8217275b57aa48d ("net:
> mdio: Delete usage of driver_deferred_probe_check_state()") in
> driver-core/driver-core-next.
>
> Seems like I missed something when providing my T-b for this series,
> sorry for that.
>
> arch/arm/boot/dts/r8a7791-koelsch.dts has:
>
>     &ether {
>             pinctrl-0 = <&ether_pins>, <&phy1_pins>;
>             pinctrl-names = "default";
>
>             phy-handle = <&phy1>;
>             renesas,ether-link-active-low;
>             status = "okay";
>
>             phy1: ethernet-phy@1 {
>                     compatible = "ethernet-phy-id0022.1537",
>                                  "ethernet-phy-ieee802.3-c22";
>                     reg = <1>;
>                     interrupt-parent = <&irqc0>;
>                     interrupts = <0 IRQ_TYPE_LEVEL_LOW>;
>                     micrel,led-mode = <1>;
>                     reset-gpios = <&gpio5 22 GPIO_ACTIVE_LOW>;
>             };
>     };
>
> Despite the interrupts property, &ether is now probed before irqc0
> (interrupt-controller@e61c0000 in arch/arm/boot/dts/r8a7791.dtsi),
> causing the PHY not finding its interrupt, and resorting to polling:
>
>     -Micrel KSZ8041RNLI ee700000.ethernet-ffffffff:01: attached PHY
> driver (mii_bus:phy_addr=ee700000.ethernet-ffffffff:01, irq=185)
>     +Micrel KSZ8041RNLI ee700000.ethernet-ffffffff:01: attached PHY
> driver (mii_bus:phy_addr=ee700000.ethernet-ffffffff:01, irq=POLL)
>
> Reverting this commit, and commit 9cbffc7a59561be9 ("driver core:
> Delete driver_deferred_probe_check_state()") fixes that.

FTR, this issue is now present in v6.0-rc1.
I haven't tried your newest series yet.

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
diff mbox series

Patch

diff --git a/drivers/net/mdio/fwnode_mdio.c b/drivers/net/mdio/fwnode_mdio.c
index 1c1584fca632..3e79c2c51929 100644
--- a/drivers/net/mdio/fwnode_mdio.c
+++ b/drivers/net/mdio/fwnode_mdio.c
@@ -47,9 +47,7 @@  int fwnode_mdiobus_phy_device_register(struct mii_bus *mdio,
 	 * just fall back to poll mode
 	 */
 	if (rc == -EPROBE_DEFER)
-		rc = driver_deferred_probe_check_state(&phy->mdio.dev);
-	if (rc == -EPROBE_DEFER)
-		return rc;
+		rc = -ENODEV;
 
 	if (rc > 0) {
 		phy->irq = rc;