2020-08-01 07:07:24

by Icenowy Zheng

Subject: [PATCH] mfd: core: Fix handle of OF disabled MFD cells

When rewriting the OF match code of MFD core, addition of cells disabled
in OF will result in a failure with error -ENODEV. This is an unexpected
behavior, as the previous behavior is silently ignore the cell. On
SBCs with AXP20x PMICs, this leads to boot failure if AXP20x PMIC
support is built-in and some cells (especially power supply ones) are
disabled.

Silently ignore the cell when -ENODEV occurs.

Fixes: e49aa9a9bd22 ("mfd: core: Make a best effort attempt to match devices with the correct of_nodes")
Signed-off-by: Icenowy Zheng <[email protected]>
---
drivers/mfd/mfd-core.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
index c3ef58a802bee..31b363c64f4b4 100644
--- a/drivers/mfd/mfd-core.c
+++ b/drivers/mfd/mfd-core.c
@@ -215,8 +215,13 @@ static int mfd_add_device(struct device *parent, int id,
ret = mfd_match_of_node_to_dev(pdev, np, cell);
if (ret == -EAGAIN)
continue;
- if (ret)
+ if (ret) {
+ if (ret == -ENODEV) {
+ /* Ignore disabled devices error free */
+ ret = 0;
+ }
goto fail_alias;
+ }

break;
}
--
2.27.0

2020-08-19 08:14:43

by Lee Jones

Subject: Re: [PATCH] mfd: core: Fix handle of OF disabled MFD cells

On Sat, 01 Aug 2020, Icenowy Zheng wrote:

> When rewriting the OF match code of MFD core, addition of cells disabled
> in OF will result in a failure with error -ENODEV. This is an unexpected
> behavior, as the previous behavior is silently ignore the cell. On
> SBCs with AXP20x PMICs, this leads to boot failure if AXP20x PMIC
> support is built-in and some cells (especially power supply ones) are
> disabled.

Thanks for reporting this.

Do you mind if I fix this another way? I plan to reinstate the old
code that was removed as part of the offending patch. I will of
course add your Reported-by tag.

> Silently ignore the cell when -ENODEV occurs.
>
> Fixes: e49aa9a9bd22 ("mfd: core: Make a best effort attempt to match devices with the correct of_nodes")
> Signed-off-by: Icenowy Zheng <[email protected]>
> ---
> drivers/mfd/mfd-core.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
> index c3ef58a802bee..31b363c64f4b4 100644
> --- a/drivers/mfd/mfd-core.c
> +++ b/drivers/mfd/mfd-core.c
> @@ -215,8 +215,13 @@ static int mfd_add_device(struct device *parent, int id,
> ret = mfd_match_of_node_to_dev(pdev, np, cell);
> if (ret == -EAGAIN)
> continue;
> - if (ret)
> + if (ret) {
> + if (ret == -ENODEV) {
> + /* Ignore disabled devices error free */
> + ret = 0;
> + }
> goto fail_alias;
> + }
>
> break;
> }

--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog

2020-08-19 08:21:08

by Icenowy Zheng

Subject: Re: [PATCH] mfd: core: Fix handle of OF disabled MFD cells

在 2020-08-19星期三的 09:11 +0100，Lee Jones写道：
> On Sat, 01 Aug 2020, Icenowy Zheng wrote:
>
> > When rewriting the OF match code of MFD core, addition of cells
> > disabled
> > in OF will result in a failure with error -ENODEV. This is an
> > unexpected
> > behavior, as the previous behavior is silently ignore the cell. On
> > SBCs with AXP20x PMICs, this leads to boot failure if AXP20x PMIC
> > support is built-in and some cells (especially power supply ones)
> > are
> > disabled.
>
> Thanks for reporting this.
>
> Do you mind if I fix this another way? I plan to reinstate the old
> code that was removed as part of the offending patch. I will of
> course add your Reported-by tag.

I think it's okay.

I will test it once it's out.

>
> > Silently ignore the cell when -ENODEV occurs.
> >
> > Fixes: e49aa9a9bd22 ("mfd: core: Make a best effort attempt to
> > match devices with the correct of_nodes")
> > Signed-off-by: Icenowy Zheng <[email protected]>
> > ---
> > drivers/mfd/mfd-core.c | 7 ++++++-
> > 1 file changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
> > index c3ef58a802bee..31b363c64f4b4 100644
> > --- a/drivers/mfd/mfd-core.c
> > +++ b/drivers/mfd/mfd-core.c
> > @@ -215,8 +215,13 @@ static int mfd_add_device(struct device
> > *parent, int id,
> > ret = mfd_match_of_node_to_dev(pdev,
> > np, cell);
> > if (ret == -EAGAIN)
> > continue;
> > - if (ret)
> > + if (ret) {
> > + if (ret == -ENODEV) {
> > + /* Ignore disabled
> > devices error free */
> > + ret = 0;
> > + }
> > goto fail_alias;
> > + }
> >
> > break;
> > }

2020-08-19 08:27:52

by Lee Jones

Subject: Re: [PATCH] mfd: core: Fix handle of OF disabled MFD cells

On Wed, 19 Aug 2020, Icenowy Zheng wrote:

> 在 2020-08-19星期三的 09:11 +0100，Lee Jones写道：
> > On Sat, 01 Aug 2020, Icenowy Zheng wrote:
> >
> > > When rewriting the OF match code of MFD core, addition of cells
> > > disabled
> > > in OF will result in a failure with error -ENODEV. This is an
> > > unexpected
> > > behavior, as the previous behavior is silently ignore the cell. On
> > > SBCs with AXP20x PMICs, this leads to boot failure if AXP20x PMIC
> > > support is built-in and some cells (especially power supply ones)
> > > are
> > > disabled.
> >
> > Thanks for reporting this.
> >
> > Do you mind if I fix this another way? I plan to reinstate the old
> > code that was removed as part of the offending patch. I will of
> > course add your Reported-by tag.
>
> I think it's okay.
>
> I will test it once it's out.

That would be great. Then I can add your Tested-by also.

--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog