diff mbox series

clk: Mark fwnodes when their clock provider is added

Message ID 20210210114435.122242-2-tudor.ambarus@microchip.com
State Accepted
Commit 6579c8d97ad7fc5671ee60234f3b8388abee5f77
Headers show
Series clk: Mark fwnodes when their clock provider is added | expand

Commit Message

Tudor Ambarus Feb. 10, 2021, 11:44 a.m. UTC
This is a follow-up for:
commit 3c9ea42802a1 ("clk: Mark fwnodes when their clock provider is added/removed")

The above commit updated the deprecated of_clk_add_provider(),
but missed to update the preferred of_clk_add_hw_provider().
Update it now.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
---
 drivers/clk/clk.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Greg Kroah-Hartman Feb. 11, 2021, 1 p.m. UTC | #1
On Wed, Feb 10, 2021 at 01:44:35PM +0200, Tudor Ambarus wrote:
> This is a follow-up for:
> commit 3c9ea42802a1 ("clk: Mark fwnodes when their clock provider is added/removed")
> 
> The above commit updated the deprecated of_clk_add_provider(),
> but missed to update the preferred of_clk_add_hw_provider().
> Update it now.
> 
> Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
> ---
>  drivers/clk/clk.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index 27ff90eacb1f..9370e4dfecae 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -4594,6 +4594,8 @@ int of_clk_add_hw_provider(struct device_node *np,
>  	if (ret < 0)
>  		of_clk_del_provider(np);
>  
> +	fwnode_dev_initialized(&np->fwnode, true);
> +
>  	return ret;
>  }
>  EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);
> -- 
> 2.25.1
> 

Any objection for me taking this in my tree as well?

thanks,

greg k-h
Stephen Boyd Feb. 13, 2021, 12:37 a.m. UTC | #2
Quoting Greg KH (2021-02-11 05:00:51)
> On Wed, Feb 10, 2021 at 01:44:35PM +0200, Tudor Ambarus wrote:
> > This is a follow-up for:
> > commit 3c9ea42802a1 ("clk: Mark fwnodes when their clock provider is added/removed")
> > 
> > The above commit updated the deprecated of_clk_add_provider(),
> > but missed to update the preferred of_clk_add_hw_provider().
> > Update it now.
> > 
> > Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
> > ---

Acked-by: Stephen Boyd <sboyd@kernel.org>
Geert Uytterhoeven March 25, 2021, 3:47 p.m. UTC | #3
Hi Marek,

On Thu, Mar 25, 2021 at 2:32 PM Marek Szyprowski
<m.szyprowski@samsung.com> wrote:
> On 10.02.2021 12:44, Tudor Ambarus wrote:
> > This is a follow-up for:
> > commit 3c9ea42802a1 ("clk: Mark fwnodes when their clock provider is added/removed")
> >
> > The above commit updated the deprecated of_clk_add_provider(),
> > but missed to update the preferred of_clk_add_hw_provider().
> > Update it now.
> >
> > Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
>
> This patch, which landed in linux-next as commit 6579c8d97ad7 ("clk:
> Mark fwnodes when their clock provider is added") causes the following
> NULL pointer dereference on Raspberry Pi 3b+ boards:
>
> --->8---
>
> raspberrypi-firmware soc:firmware: Attached to firmware from
> 2020-01-06T13:05:25
> Unable to handle kernel NULL pointer dereference at virtual address
> 0000000000000050
> Mem abort info:
>    ESR = 0x96000004
>    EC = 0x25: DABT (current EL), IL = 32 bits
>    SET = 0, FnV = 0
>    EA = 0, S1PTW = 0
> Data abort info:
>    ISV = 0, ISS = 0x00000004
>    CM = 0, WnR = 0
> [0000000000000050] user address but active_mm is swapper
> Internal error: Oops: 96000004 [#1] PREEMPT SMP
> Modules linked in:
> CPU: 0 PID: 10 Comm: kworker/0:1 Not tainted 5.12.0-rc4+ #2764
> Hardware name: Raspberry Pi 3 Model B (DT)
> Workqueue: events deferred_probe_work_func
> pstate: 00000005 (nzcv daif -PAN -UAO -TCO BTYPE=--)
> pc : of_clk_add_hw_provider+0xac/0xe8
> lr : of_clk_add_hw_provider+0x94/0xe8
> sp : ffff8000130936b0
> x29: ffff8000130936b0 x28: ffff800012494e04
> x27: ffff00003b18cb05 x26: ffff00003aa5c010
> x25: 0000000000000000 x24: 0000000000000000
> x23: ffff00003aa1e380 x22: ffff8000106830d0
> x21: ffff80001233f180 x20: 0000000000000018
> x19: 0000000000000000 x18: ffff8000124d38b0
> x17: 0000000000000013 x16: 0000000000000014
> x15: ffff8000125758b0 x14: 00000000000184e0
> x13: 000000000000292e x12: ffff80001258dd98
> x11: 0000000000000001 x10: 0101010101010101
> x9 : ffff80001233f288 x8 : 7f7f7f7f7f7f7f7f
> x7 : fefefefeff6c626f x6 : 5d636d8080808080
> x5 : 00000000006d635d x4 : 0000000000000000
> x3 : 0000000000000000 x2 : 540eb5edae191600
> x1 : 0000000000000000 x0 : 0000000000000000
> Call trace:
>   of_clk_add_hw_provider+0xac/0xe8
>   devm_of_clk_add_hw_provider+0x5c/0xb8
>   raspberrypi_clk_probe+0x110/0x210
>   platform_probe+0x90/0xd8
>   really_probe+0x108/0x3c0
>   driver_probe_device+0x60/0xc0
>   __device_attach_driver+0x9c/0xd0
>   bus_for_each_drv+0x70/0xc8
>   __device_attach+0xec/0x150
>   device_initial_probe+0x10/0x18
>   bus_probe_device+0x94/0xa0
>   device_add+0x47c/0x780
>   platform_device_add+0x110/0x248
>   platform_device_register_full+0x120/0x150
>   rpi_firmware_probe+0x158/0x1f8

> This patch mainly revealed that clk/bcm/clk-raspberrypi.c driver calls
> devm_of_clk_add_hw_provider(), with a device pointer, which has a NULL
> dev->of_node. I'm not sure if adding a check for a NULL np in
> of_clk_add_hw_provider() is a right fix, though.

raspberrypi_clk_probe():

        /*
         * We can be probed either through the an old-fashioned
         * platform device registration or through a DT node that is a
         * child of the firmware node. Handle both cases.
         */

So the real issue is rpi_register_clk_driver() creating a platform
device for the firmware clocks if they're missing in DT.

Then, the clock driver calls devm_of_clk_add_hw_provider(),
regardless of a DT node being present or not.
I'm wondering how power consumers are supposed to refer
to these firmware clocks, without a DT node?

> > --- a/drivers/clk/clk.c
> > +++ b/drivers/clk/clk.c
> > @@ -4594,6 +4594,8 @@ int of_clk_add_hw_provider(struct device_node *np,
> >       if (ret < 0)
> >               of_clk_del_provider(np);
> >
> > +     fwnode_dev_initialized(&np->fwnode, true);
> > +
> >       return ret;
> >   }
> >   EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);

Gr{oetje,eeting}s,

                        Geert
Geert Uytterhoeven March 26, 2021, 6:29 p.m. UTC | #4
Hi Stephen,

On Fri, Mar 26, 2021 at 7:13 PM Stephen Boyd <sboyd@kernel.org> wrote:
> Quoting Nicolas Saenz Julienne (2021-03-25 11:25:24)

> > On Thu, 2021-03-25 at 14:31 +0100, Marek Szyprowski wrote:

> > > On 10.02.2021 12:44, Tudor Ambarus wrote:

> > > > This is a follow-up for:

> > > > commit 3c9ea42802a1 ("clk: Mark fwnodes when their clock provider is added/removed")

> > > >

> > > > The above commit updated the deprecated of_clk_add_provider(),

> > > > but missed to update the preferred of_clk_add_hw_provider().

> > > > Update it now.

> > > >

> > > > Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>

> > >

> > > This patch, which landed in linux-next as commit 6579c8d97ad7 ("clk:

> > > Mark fwnodes when their clock provider is added") causes the following

> > > NULL pointer dereference on Raspberry Pi 3b+ boards:

> > >

> > > --->8---

> > >

> > > raspberrypi-firmware soc:firmware: Attached to firmware from

> > > 2020-01-06T13:05:25

> > > Unable to handle kernel NULL pointer dereference at virtual address

> > > 0000000000000050

> > > Mem abort info:

> > >    ESR = 0x96000004

> > >    EC = 0x25: DABT (current EL), IL = 32 bits

> > >    SET = 0, FnV = 0

> > >    EA = 0, S1PTW = 0

> > > Data abort info:

> > >    ISV = 0, ISS = 0x00000004

> > >    CM = 0, WnR = 0

> > > [0000000000000050] user address but active_mm is swapper

> > > Internal error: Oops: 96000004 [#1] PREEMPT SMP

> > > Modules linked in:

> > > CPU: 0 PID: 10 Comm: kworker/0:1 Not tainted 5.12.0-rc4+ #2764

> > > Hardware name: Raspberry Pi 3 Model B (DT)

> > > Workqueue: events deferred_probe_work_func

> > > pstate: 00000005 (nzcv daif -PAN -UAO -TCO BTYPE=--)

> > > pc : of_clk_add_hw_provider+0xac/0xe8

> > > lr : of_clk_add_hw_provider+0x94/0xe8

> > > sp : ffff8000130936b0

> > > x29: ffff8000130936b0 x28: ffff800012494e04

> > > x27: ffff00003b18cb05 x26: ffff00003aa5c010

> > > x25: 0000000000000000 x24: 0000000000000000

> > > x23: ffff00003aa1e380 x22: ffff8000106830d0

> > > x21: ffff80001233f180 x20: 0000000000000018

> > > x19: 0000000000000000 x18: ffff8000124d38b0

> > > x17: 0000000000000013 x16: 0000000000000014

> > > x15: ffff8000125758b0 x14: 00000000000184e0

> > > x13: 000000000000292e x12: ffff80001258dd98

> > > x11: 0000000000000001 x10: 0101010101010101

> > > x9 : ffff80001233f288 x8 : 7f7f7f7f7f7f7f7f

> > > x7 : fefefefeff6c626f x6 : 5d636d8080808080

> > > x5 : 00000000006d635d x4 : 0000000000000000

> > > x3 : 0000000000000000 x2 : 540eb5edae191600

> > > x1 : 0000000000000000 x0 : 0000000000000000

> > > Call trace:

> > >   of_clk_add_hw_provider+0xac/0xe8

> > >   devm_of_clk_add_hw_provider+0x5c/0xb8

> > >   raspberrypi_clk_probe+0x110/0x210

> > >   platform_probe+0x90/0xd8

> > >   really_probe+0x108/0x3c0

> > >   driver_probe_device+0x60/0xc0

> > >   __device_attach_driver+0x9c/0xd0

> > >   bus_for_each_drv+0x70/0xc8

> > >   __device_attach+0xec/0x150

> > >   device_initial_probe+0x10/0x18

> > >   bus_probe_device+0x94/0xa0

> > >   device_add+0x47c/0x780

> > >   platform_device_add+0x110/0x248

> > >   platform_device_register_full+0x120/0x150

> > >   rpi_firmware_probe+0x158/0x1f8

> > >   platform_probe+0x90/0xd8

> > >   really_probe+0x108/0x3c0

> > >   driver_probe_device+0x60/0xc0

> > >   __device_attach_driver+0x9c/0xd0

> > >   bus_for_each_drv+0x70/0xc8

> > >   __device_attach+0xec/0x150

> > >   device_initial_probe+0x10/0x18

> > >   bus_probe_device+0x94/0xa0

> > >   deferred_probe_work_func+0x70/0xa8

> > >   process_one_work+0x2a8/0x718

> > >   worker_thread+0x48/0x460

> > >   kthread+0x134/0x160

> > >   ret_from_fork+0x10/0x18

> > > Code: b1006294 540000c0 b140069f 54000088 (3940e280)

> > > ---[ end trace 7ead5ec2f0c51cfe ]---

> > >

> > > This patch mainly revealed that clk/bcm/clk-raspberrypi.c driver calls

> > > devm_of_clk_add_hw_provider(), with a device pointer, which has a NULL

> > > dev->of_node. I'm not sure if adding a check for a NULL np in

> > > of_clk_add_hw_provider() is a right fix, though.

> >

> > I believe the right fix is not to call 'devm_of_clk_add_hw_provider()' if

> > 'pdev->dev.of_node == NULL'. In such case, which is RPi3's, only the CPU clock

> > is used, and it's defined and queried later through

> > devm_clk_hw_register_clkdev().

> >

> > @Marek, I don't mind taking care of it if it's OK with you.

> >

>

> Ah I see this is related to the patch I just reviewed. Can you reference

> this in the commit text? And instead of putting the change into the clk

> provider let's check for NULL 'np' in of_clk_add_hw_provider() instead

> and return 0 if there's nothing to do. That way we don't visit this

> problem over and over again.


I'm not sure the latter is what we reall want: shouldn't calling
*of*_clk_add_hw_provider() with a NULL np be a bug in the provider?

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 March 29, 2021, 11:28 p.m. UTC | #5
On Mon, Mar 29, 2021 at 2:25 PM Stephen Boyd <sboyd@kernel.org> wrote:
>

> Quoting Geert Uytterhoeven (2021-03-26 11:29:55)

> > On Fri, Mar 26, 2021 at 7:13 PM Stephen Boyd <sboyd@kernel.org> wrote:

> > > Quoting Nicolas Saenz Julienne (2021-03-25 11:25:24)

> > > > >

> > > > > This patch mainly revealed that clk/bcm/clk-raspberrypi.c driver calls

> > > > > devm_of_clk_add_hw_provider(), with a device pointer, which has a NULL

> > > > > dev->of_node. I'm not sure if adding a check for a NULL np in

> > > > > of_clk_add_hw_provider() is a right fix, though.

> > > >

> > > > I believe the right fix is not to call 'devm_of_clk_add_hw_provider()' if

> > > > 'pdev->dev.of_node == NULL'. In such case, which is RPi3's, only the CPU clock

> > > > is used, and it's defined and queried later through

> > > > devm_clk_hw_register_clkdev().

> > > >

> > > > @Marek, I don't mind taking care of it if it's OK with you.

> > > >

> > >

> > > Ah I see this is related to the patch I just reviewed. Can you reference

> > > this in the commit text? And instead of putting the change into the clk

> > > provider let's check for NULL 'np' in of_clk_add_hw_provider() instead

> > > and return 0 if there's nothing to do. That way we don't visit this

> > > problem over and over again.

> >

> > I'm not sure the latter is what we reall want: shouldn't calling

> > *of*_clk_add_hw_provider() with a NULL np be a bug in the provider?

> >

>

> I don't have a strong opinion either way. Would it be useful if the

> function returned an error when 'np' is NULL?


I lean towards returning an error. Not a strong opinion either.

-Saravana

> I guess the caller could

> use that to figure out that it should register a clkdev. But it

> shouldn't hurt to register both a clkdev lookup and a DT provider for

> the same clk. The framework will try the DT path first and then fallback

> to a clkdev lookup otherwise, so we'll be wasting memory for clkdev but

> otherwise be fine.

>

> Really it feels like we should try to unify around a

> devm_clk_add_hw_provider() API that figures out what to do based on if

> the device has an of_node or not. That would mean implementing something

> like clkdev but for a whole provider instead of a single clk. Then this

> question of returning an error would be moot here.
Geert Uytterhoeven March 30, 2021, 6:58 a.m. UTC | #6
Hi Stephen,

On Tue, Mar 30, 2021 at 3:53 AM Stephen Boyd <sboyd@kernel.org> wrote:
> Quoting Saravana Kannan (2021-03-29 16:28:20)

> > On Mon, Mar 29, 2021 at 2:25 PM Stephen Boyd <sboyd@kernel.org> wrote:

> > > Quoting Geert Uytterhoeven (2021-03-26 11:29:55)

> > > > On Fri, Mar 26, 2021 at 7:13 PM Stephen Boyd <sboyd@kernel.org> wrote:

> > > > > Quoting Nicolas Saenz Julienne (2021-03-25 11:25:24)

> > > > > > >

> > > > > > > This patch mainly revealed that clk/bcm/clk-raspberrypi.c driver calls

> > > > > > > devm_of_clk_add_hw_provider(), with a device pointer, which has a NULL

> > > > > > > dev->of_node. I'm not sure if adding a check for a NULL np in

> > > > > > > of_clk_add_hw_provider() is a right fix, though.

> > > > > >

> > > > > > I believe the right fix is not to call 'devm_of_clk_add_hw_provider()' if

> > > > > > 'pdev->dev.of_node == NULL'. In such case, which is RPi3's, only the CPU clock

> > > > > > is used, and it's defined and queried later through

> > > > > > devm_clk_hw_register_clkdev().

> > > > > >

> > > > > > @Marek, I don't mind taking care of it if it's OK with you.

> > > > > >

> > > > >

> > > > > Ah I see this is related to the patch I just reviewed. Can you reference

> > > > > this in the commit text? And instead of putting the change into the clk

> > > > > provider let's check for NULL 'np' in of_clk_add_hw_provider() instead

> > > > > and return 0 if there's nothing to do. That way we don't visit this

> > > > > problem over and over again.

> > > >

> > > > I'm not sure the latter is what we reall want: shouldn't calling

> > > > *of*_clk_add_hw_provider() with a NULL np be a bug in the provider?

> > > >

> > >

> > > I don't have a strong opinion either way. Would it be useful if the

> > > function returned an error when 'np' is NULL?

> >

> > I lean towards returning an error. Not a strong opinion either.

>

> Does it have any use?


of_clk_del_provider() removes the first provider found with node == NULL.
If there are two drivers calling of_clk_add_hw_provider(), and one of
hem calls of_clk_del_provider() later, the wrong provider may be
removed from the list.

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 March 31, 2021, 7:05 a.m. UTC | #7
Hi Stephen,

On Wed, Mar 31, 2021 at 4:22 AM Stephen Boyd <sboyd@kernel.org> wrote:
> Quoting Geert Uytterhoeven (2021-03-29 23:58:23)

> > On Tue, Mar 30, 2021 at 3:53 AM Stephen Boyd <sboyd@kernel.org> wrote:

> > > Quoting Saravana Kannan (2021-03-29 16:28:20)

> > > > On Mon, Mar 29, 2021 at 2:25 PM Stephen Boyd <sboyd@kernel.org> wrote:

> > > > > Quoting Geert Uytterhoeven (2021-03-26 11:29:55)

> > > > > > On Fri, Mar 26, 2021 at 7:13 PM Stephen Boyd <sboyd@kernel.org> wrote:

> > > > > > > Quoting Nicolas Saenz Julienne (2021-03-25 11:25:24)

> > > > > > > > >

> > > > > > > > > This patch mainly revealed that clk/bcm/clk-raspberrypi.c driver calls

> > > > > > > > > devm_of_clk_add_hw_provider(), with a device pointer, which has a NULL

> > > > > > > > > dev->of_node. I'm not sure if adding a check for a NULL np in

> > > > > > > > > of_clk_add_hw_provider() is a right fix, though.

> > > > > > > >

> > > > > > > > I believe the right fix is not to call 'devm_of_clk_add_hw_provider()' if

> > > > > > > > 'pdev->dev.of_node == NULL'. In such case, which is RPi3's, only the CPU clock

> > > > > > > > is used, and it's defined and queried later through

> > > > > > > > devm_clk_hw_register_clkdev().

> > > > > > > >

> > > > > > > > @Marek, I don't mind taking care of it if it's OK with you.

> > > > > > > >

> > > > > > >

> > > > > > > Ah I see this is related to the patch I just reviewed. Can you reference

> > > > > > > this in the commit text? And instead of putting the change into the clk

> > > > > > > provider let's check for NULL 'np' in of_clk_add_hw_provider() instead

> > > > > > > and return 0 if there's nothing to do. That way we don't visit this

> > > > > > > problem over and over again.

> > > > > >

> > > > > > I'm not sure the latter is what we reall want: shouldn't calling

> > > > > > *of*_clk_add_hw_provider() with a NULL np be a bug in the provider?

> > > > > >

> > > > >

> > > > > I don't have a strong opinion either way. Would it be useful if the

> > > > > function returned an error when 'np' is NULL?

> > > >

> > > > I lean towards returning an error. Not a strong opinion either.

> > >

> > > Does it have any use?

> >

> > of_clk_del_provider() removes the first provider found with node == NULL.

> > If there are two drivers calling of_clk_add_hw_provider(), and one of

> > hem calls of_clk_del_provider() later, the wrong provider may be

> > removed from the list.

> >

>

> So you're saying we shouldn't add a NULL device node pointer to the list

> so that this can't happen? That doesn't mean returning an error from

> of_clk_add_hw_provider() would be useful though.

> of_clk_add_hw_provider() can return 0 if np == NULL and

> of_clk_del_provider() can return early if np == NULL too.


I don't know if I grasp all meanings of the above.

The main question is if it is valid for a driver to call
of_clk_add_hw_provider()
with np == NULL.
  - If yes, should that register the provider?
      - If yes, how to handle two drivers calling of_clk_add_hw_provider()
        with np = NULL, as their unregistration order is not guaranteed to
        be correct.

If no, is that something to ignore (0), or a bug (error)?

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
Nicolas Saenz Julienne April 5, 2021, 11:04 a.m. UTC | #8
On Wed, 2021-03-31 at 12:25 -0700, Stephen Boyd wrote:
> Quoting Geert Uytterhoeven (2021-03-31 00:05:00)

> > On Wed, Mar 31, 2021 at 4:22 AM Stephen Boyd <sboyd@kernel.org> wrote:

> > > > > Does it have any use?

> > > > 

> > > > of_clk_del_provider() removes the first provider found with node == NULL.

> > > > If there are two drivers calling of_clk_add_hw_provider(), and one of

> > > > hem calls of_clk_del_provider() later, the wrong provider may be

> > > > removed from the list.

> > > > 

> > > 

> > > So you're saying we shouldn't add a NULL device node pointer to the list

> > > so that this can't happen? That doesn't mean returning an error from

> > > of_clk_add_hw_provider() would be useful though.

> > > of_clk_add_hw_provider() can return 0 if np == NULL and

> > > of_clk_del_provider() can return early if np == NULL too.

> > 

> > I don't know if I grasp all meanings of the above.

> > 

> > The main question is if it is valid for a driver to call

> > of_clk_add_hw_provider()

> > with np == NULL.

> >   - If yes, should that register the provider?

> 

> No it should not register the provider. That would be bad as you pointed

> out.

> 

> >       - If yes, how to handle two drivers calling of_clk_add_hw_provider()

> >         with np = NULL, as their unregistration order is not guaranteed to

> >         be correct.

> > 

> > If no, is that something to ignore (0), or a bug (error)?

> 

> This is my question above. Is there a use to having

> of_clk_add_hw_provider() return an error value when np == NULL? I doubt

> it.

> 

> Returning 0 would reduce the if conditions in driver code in this case

> and be consistent with the CONFIG_OF=n inline stub that returns 0 when

> CONFIG_OF is disabled. The only case an error would be returned is if we

> couldn't allocate memory or if the assigned clocks code failed. Seems

> sane to me. The downside is that drivers would maybe register clkdev

> lookups when they don't need to and waste some memory. I'm fine with

> that until we have some sort of non-DT based clk provider lookup

> mechanism that could unify the two methods.


What about devm_of_clk_add_hw_provider() users, do we care that a seemingly
empty managed resource will be created?

Regards,
Nicolas
Guenter Roeck April 21, 2021, 3:26 a.m. UTC | #9
Hi,

On Wed, Feb 10, 2021 at 01:44:35PM +0200, Tudor Ambarus wrote:
> This is a follow-up for:
> commit 3c9ea42802a1 ("clk: Mark fwnodes when their clock provider is added/removed")
> 
> The above commit updated the deprecated of_clk_add_provider(),
> but missed to update the preferred of_clk_add_hw_provider().
> Update it now.
> 
> Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>

This patch still causes a crash when booting a raspi2 image in linux-next.

[   21.456500] Unable to handle kernel NULL pointer dereference at virtual address 00000028
[   21.456750] pgd = (ptrval)
[   21.456927] [00000028] *pgd=00000000
[   21.457567] Internal error: Oops: 5 [#1] SMP ARM
[   21.457882] Modules linked in:
[   21.458077] CPU: 0 PID: 77 Comm: kworker/u8:10 Not tainted 5.12.0-rc8-next-20210420 #1
[   21.458291] Hardware name: BCM2835
[   21.458525] Workqueue: events_unbound deferred_probe_work_func
[   21.458997] PC is at of_clk_add_hw_provider+0xbc/0xe8
[   21.459176] LR is at of_clk_add_hw_provider+0xa8/0xe8
...
[   21.477603] [<c0a32aec>] (of_clk_add_hw_provider) from [<c0a32b60>] (devm_of_clk_add_hw_provider+0x48/0x80)
[   21.477861] [<c0a32b60>] (devm_of_clk_add_hw_provider) from [<c0a471e4>] (raspberrypi_clk_probe+0x260/0x388)
[   21.478087] [<c0a471e4>] (raspberrypi_clk_probe) from [<c0c1c4d0>] (platform_probe+0x5c/0xb8)
[   21.478287] [<c0c1c4d0>] (platform_probe) from [<c0c19d84>] (really_probe+0xf0/0x39c)
[   21.478471] [<c0c19d84>] (really_probe) from [<c0c1a098>] (driver_probe_device+0x68/0xc0)
[   21.478659] [<c0c1a098>] (driver_probe_device) from [<c0c17f54>] (bus_for_each_drv+0x84/0xc8)
[   21.478860] [<c0c17f54>] (bus_for_each_drv) from [<c0c19c20>] (__device_attach+0xec/0x158)
[   21.479050] [<c0c19c20>] (__device_attach) from [<c0c18de8>] (bus_probe_device+0x88/0x90)
[   21.479236] [<c0c18de8>] (bus_probe_device) from [<c0c16a68>] (device_add+0x398/0x8ac)
[   21.479421] [<c0c16a68>] (device_add) from [<c0c1c1b4>] (platform_device_add+0xf0/0x200)
[   21.479607] [<c0c1c1b4>] (platform_device_add) from [<c0c1ccc0>] (platform_device_register_full+0xd0/0x110)
[   21.479836] [<c0c1ccc0>] (platform_device_register_full) from [<c104c130>] (rpi_firmware_probe+0x1a4/0x20c)
[   21.480061] [<c104c130>] (rpi_firmware_probe) from [<c0c1c4d0>] (platform_probe+0x5c/0xb8)
[   21.480255] [<c0c1c4d0>] (platform_probe) from [<c0c19d84>] (really_probe+0xf0/0x39c)
[   21.480437] [<c0c19d84>] (really_probe) from [<c0c1a098>] (driver_probe_device+0x68/0xc0)
[   21.480626] [<c0c1a098>] (driver_probe_device) from [<c0c17f54>] (bus_for_each_drv+0x84/0xc8)
[   21.480829] [<c0c17f54>] (bus_for_each_drv) from [<c0c19c20>] (__device_attach+0xec/0x158)
[   21.481018] [<c0c19c20>] (__device_attach) from [<c0c18de8>] (bus_probe_device+0x88/0x90)
[   21.481205] [<c0c18de8>] (bus_probe_device) from [<c0c192bc>] (deferred_probe_work_func+0x8c/0xbc)
[   21.481413] [<c0c192bc>] (deferred_probe_work_func) from [<c036802c>] (process_one_work+0x268/0x798)
[   21.481624] [<c036802c>] (process_one_work) from [<c0368774>] (worker_thread+0x218/0x4f4)
[   21.481822] [<c0368774>] (worker_thread) from [<c0370f28>] (kthread+0x140/0x174)
[   21.481999] [<c0370f28>] (kthread) from [<c030017c>] (ret_from_fork+0x14/0x38)
[   21.482185] Exception stack(0xc42b7fb0 to 0xc42b7ff8)

Updated bisect log is attached.

Guenter

---
# bad: [50b8b1d699ac313c0a07a3c185ffb23aecab8abb] Add linux-next specific files for 20210419
# good: [bf05bf16c76bb44ab5156223e1e58e26dfe30a88] Linux 5.12-rc8
git bisect start 'HEAD' 'v5.12-rc8'
# good: [c4bb91fc07e59241cde97f913d7a2fbedc248f0d] Merge remote-tracking branch 'crypto/master'
git bisect good c4bb91fc07e59241cde97f913d7a2fbedc248f0d
# good: [f15bbf170b40b48a43ed7076ce9f8ac9380e5752] Merge remote-tracking branch 'edac/edac-for-next'
git bisect good f15bbf170b40b48a43ed7076ce9f8ac9380e5752
# bad: [550a78090dcc4061e191312a757a127f0b6e6323] Merge remote-tracking branch 'vfio/next'
git bisect bad 550a78090dcc4061e191312a757a127f0b6e6323
# bad: [9f074d2a7bf49b2c9e1609703757b18de7611aef] Merge remote-tracking branch 'usb/usb-next'
git bisect bad 9f074d2a7bf49b2c9e1609703757b18de7611aef
# good: [855b2fdb7c543c94e7623e6ad0b492f04a5317db] Merge remote-tracking branch 'percpu/for-next'
git bisect good 855b2fdb7c543c94e7623e6ad0b492f04a5317db
# good: [1d08ed588c6a85a35a24c82eb4cf0807ec2b366a] usbip: vudc: fix missing unlock on error in usbip_sockfd_store()
git bisect good 1d08ed588c6a85a35a24c82eb4cf0807ec2b366a
# good: [1b7ce8fab5fd0c406dbf165b12d44b301decf589] Merge remote-tracking branch 'ipmi/for-next'
git bisect good 1b7ce8fab5fd0c406dbf165b12d44b301decf589
# good: [fe8e488058c47e9a8a2c85321f7198a0a17b0131] dt-bindings: usb: mtk-xhci: add wakeup interrupt
git bisect good fe8e488058c47e9a8a2c85321f7198a0a17b0131
# bad: [3c652132ce9052e626bf509932fcacfebed1ccb4] platform-msi: fix kernel-doc warnings
git bisect bad 3c652132ce9052e626bf509932fcacfebed1ccb4
# bad: [7f2fac70b729d68a34e5eba8d1fb68eb69b05169] device property: Add test cases for fwnode_property_count_*() APIs
git bisect bad 7f2fac70b729d68a34e5eba8d1fb68eb69b05169
# good: [38f087de8947700d3b06d3d1594490e0f611c5d1] devtmpfs: fix placement of complete() call
git bisect good 38f087de8947700d3b06d3d1594490e0f611c5d1
# good: [b6f617df4fa936c1ab1831c2b23563f6c1add6c4] driver core: Update device link status properly for device_bind_driver()
git bisect good b6f617df4fa936c1ab1831c2b23563f6c1add6c4
# bad: [6579c8d97ad7fc5671ee60234f3b8388abee5f77] clk: Mark fwnodes when their clock provider is added
git bisect bad 6579c8d97ad7fc5671ee60234f3b8388abee5f77
# good: [ea718c699055c8566eb64432388a04974c43b2ea] Revert "Revert "driver core: Set fw_devlink=on by default""
git bisect good ea718c699055c8566eb64432388a04974c43b2ea
# first bad commit: [6579c8d97ad7fc5671ee60234f3b8388abee5f77] clk: Mark fwnodes when their clock provider is added
Saravana Kannan April 21, 2021, 7 a.m. UTC | #10
On Tue, Apr 20, 2021 at 8:27 PM Guenter Roeck <linux@roeck-us.net> wrote:
>

> Hi,

>

> On Wed, Feb 10, 2021 at 01:44:35PM +0200, Tudor Ambarus wrote:

> > This is a follow-up for:

> > commit 3c9ea42802a1 ("clk: Mark fwnodes when their clock provider is added/removed")

> >

> > The above commit updated the deprecated of_clk_add_provider(),

> > but missed to update the preferred of_clk_add_hw_provider().

> > Update it now.

> >

> > Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>

>

> This patch still causes a crash when booting a raspi2 image in linux-next.


Stephen,

Can we please just pick any one of the proposed fixes? This bug has
been unfixed for so long!

-Saravana

>

> [   21.456500] Unable to handle kernel NULL pointer dereference at virtual address 00000028

> [   21.456750] pgd = (ptrval)

> [   21.456927] [00000028] *pgd=00000000

> [   21.457567] Internal error: Oops: 5 [#1] SMP ARM

> [   21.457882] Modules linked in:

> [   21.458077] CPU: 0 PID: 77 Comm: kworker/u8:10 Not tainted 5.12.0-rc8-next-20210420 #1

> [   21.458291] Hardware name: BCM2835

> [   21.458525] Workqueue: events_unbound deferred_probe_work_func

> [   21.458997] PC is at of_clk_add_hw_provider+0xbc/0xe8

> [   21.459176] LR is at of_clk_add_hw_provider+0xa8/0xe8

> ...

> [   21.477603] [<c0a32aec>] (of_clk_add_hw_provider) from [<c0a32b60>] (devm_of_clk_add_hw_provider+0x48/0x80)

> [   21.477861] [<c0a32b60>] (devm_of_clk_add_hw_provider) from [<c0a471e4>] (raspberrypi_clk_probe+0x260/0x388)

> [   21.478087] [<c0a471e4>] (raspberrypi_clk_probe) from [<c0c1c4d0>] (platform_probe+0x5c/0xb8)

> [   21.478287] [<c0c1c4d0>] (platform_probe) from [<c0c19d84>] (really_probe+0xf0/0x39c)

> [   21.478471] [<c0c19d84>] (really_probe) from [<c0c1a098>] (driver_probe_device+0x68/0xc0)

> [   21.478659] [<c0c1a098>] (driver_probe_device) from [<c0c17f54>] (bus_for_each_drv+0x84/0xc8)

> [   21.478860] [<c0c17f54>] (bus_for_each_drv) from [<c0c19c20>] (__device_attach+0xec/0x158)

> [   21.479050] [<c0c19c20>] (__device_attach) from [<c0c18de8>] (bus_probe_device+0x88/0x90)

> [   21.479236] [<c0c18de8>] (bus_probe_device) from [<c0c16a68>] (device_add+0x398/0x8ac)

> [   21.479421] [<c0c16a68>] (device_add) from [<c0c1c1b4>] (platform_device_add+0xf0/0x200)

> [   21.479607] [<c0c1c1b4>] (platform_device_add) from [<c0c1ccc0>] (platform_device_register_full+0xd0/0x110)

> [   21.479836] [<c0c1ccc0>] (platform_device_register_full) from [<c104c130>] (rpi_firmware_probe+0x1a4/0x20c)

> [   21.480061] [<c104c130>] (rpi_firmware_probe) from [<c0c1c4d0>] (platform_probe+0x5c/0xb8)

> [   21.480255] [<c0c1c4d0>] (platform_probe) from [<c0c19d84>] (really_probe+0xf0/0x39c)

> [   21.480437] [<c0c19d84>] (really_probe) from [<c0c1a098>] (driver_probe_device+0x68/0xc0)

> [   21.480626] [<c0c1a098>] (driver_probe_device) from [<c0c17f54>] (bus_for_each_drv+0x84/0xc8)

> [   21.480829] [<c0c17f54>] (bus_for_each_drv) from [<c0c19c20>] (__device_attach+0xec/0x158)

> [   21.481018] [<c0c19c20>] (__device_attach) from [<c0c18de8>] (bus_probe_device+0x88/0x90)

> [   21.481205] [<c0c18de8>] (bus_probe_device) from [<c0c192bc>] (deferred_probe_work_func+0x8c/0xbc)

> [   21.481413] [<c0c192bc>] (deferred_probe_work_func) from [<c036802c>] (process_one_work+0x268/0x798)

> [   21.481624] [<c036802c>] (process_one_work) from [<c0368774>] (worker_thread+0x218/0x4f4)

> [   21.481822] [<c0368774>] (worker_thread) from [<c0370f28>] (kthread+0x140/0x174)

> [   21.481999] [<c0370f28>] (kthread) from [<c030017c>] (ret_from_fork+0x14/0x38)

> [   21.482185] Exception stack(0xc42b7fb0 to 0xc42b7ff8)

>

> Updated bisect log is attached.

>

> Guenter

>

> ---

> # bad: [50b8b1d699ac313c0a07a3c185ffb23aecab8abb] Add linux-next specific files for 20210419

> # good: [bf05bf16c76bb44ab5156223e1e58e26dfe30a88] Linux 5.12-rc8

> git bisect start 'HEAD' 'v5.12-rc8'

> # good: [c4bb91fc07e59241cde97f913d7a2fbedc248f0d] Merge remote-tracking branch 'crypto/master'

> git bisect good c4bb91fc07e59241cde97f913d7a2fbedc248f0d

> # good: [f15bbf170b40b48a43ed7076ce9f8ac9380e5752] Merge remote-tracking branch 'edac/edac-for-next'

> git bisect good f15bbf170b40b48a43ed7076ce9f8ac9380e5752

> # bad: [550a78090dcc4061e191312a757a127f0b6e6323] Merge remote-tracking branch 'vfio/next'

> git bisect bad 550a78090dcc4061e191312a757a127f0b6e6323

> # bad: [9f074d2a7bf49b2c9e1609703757b18de7611aef] Merge remote-tracking branch 'usb/usb-next'

> git bisect bad 9f074d2a7bf49b2c9e1609703757b18de7611aef

> # good: [855b2fdb7c543c94e7623e6ad0b492f04a5317db] Merge remote-tracking branch 'percpu/for-next'

> git bisect good 855b2fdb7c543c94e7623e6ad0b492f04a5317db

> # good: [1d08ed588c6a85a35a24c82eb4cf0807ec2b366a] usbip: vudc: fix missing unlock on error in usbip_sockfd_store()

> git bisect good 1d08ed588c6a85a35a24c82eb4cf0807ec2b366a

> # good: [1b7ce8fab5fd0c406dbf165b12d44b301decf589] Merge remote-tracking branch 'ipmi/for-next'

> git bisect good 1b7ce8fab5fd0c406dbf165b12d44b301decf589

> # good: [fe8e488058c47e9a8a2c85321f7198a0a17b0131] dt-bindings: usb: mtk-xhci: add wakeup interrupt

> git bisect good fe8e488058c47e9a8a2c85321f7198a0a17b0131

> # bad: [3c652132ce9052e626bf509932fcacfebed1ccb4] platform-msi: fix kernel-doc warnings

> git bisect bad 3c652132ce9052e626bf509932fcacfebed1ccb4

> # bad: [7f2fac70b729d68a34e5eba8d1fb68eb69b05169] device property: Add test cases for fwnode_property_count_*() APIs

> git bisect bad 7f2fac70b729d68a34e5eba8d1fb68eb69b05169

> # good: [38f087de8947700d3b06d3d1594490e0f611c5d1] devtmpfs: fix placement of complete() call

> git bisect good 38f087de8947700d3b06d3d1594490e0f611c5d1

> # good: [b6f617df4fa936c1ab1831c2b23563f6c1add6c4] driver core: Update device link status properly for device_bind_driver()

> git bisect good b6f617df4fa936c1ab1831c2b23563f6c1add6c4

> # bad: [6579c8d97ad7fc5671ee60234f3b8388abee5f77] clk: Mark fwnodes when their clock provider is added

> git bisect bad 6579c8d97ad7fc5671ee60234f3b8388abee5f77

> # good: [ea718c699055c8566eb64432388a04974c43b2ea] Revert "Revert "driver core: Set fw_devlink=on by default""

> git bisect good ea718c699055c8566eb64432388a04974c43b2ea

> # first bad commit: [6579c8d97ad7fc5671ee60234f3b8388abee5f77] clk: Mark fwnodes when their clock provider is added
diff mbox series

Patch

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 27ff90eacb1f..9370e4dfecae 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -4594,6 +4594,8 @@  int of_clk_add_hw_provider(struct device_node *np,
 	if (ret < 0)
 		of_clk_del_provider(np);
 
+	fwnode_dev_initialized(&np->fwnode, true);
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);