Re: [RESEND PATCH v1 2/4] dt-bindings: power: reset: Add alternate reboot mode format

[Elliot Berman]

On 8/25/2020 5:25 PM, Rob Herring wrote:
> On Tue, Aug 18, 2020 at 11:54:14AM -0700, Elliot Berman wrote:
> > Current reboot-mode device tree schema does not support reboot commands
> > with spaces in them [1]. Add an optional new node "reboot-mode-names"
> > and "reboot-mode-magic" which add an array of strings and u32s,
> > respectively which would permit any string in this framework.
>
> Kind of a weak justification. The intent was for the names to be a key,
> not a multi word description which your example seems to be. Is
> "dm-verity device corrupted" something Android has already standardized
> on?

+Eric/Sami to comment further

I wonder if you're thinking it's better to change the kernel_restart in 
dm-verity-target.c?

Alternatively, I could respin so that spaces in the reboot cmd is 
replaced with "-" in reboot_mode_notify(). This way, there is no need to 
change dm-verity driver or change devicetree schema. i.e.:

@@ -44,9 +44,13 @@ static int reboot_mode_notify(struct notifier_block 
*this,
 {
        struct reboot_mode_driver *reboot;
        unsigned int magic;
+       char *reboot_cmd;
+
+       reboot_cmd = kstrdup(cmd, GFP_KERNEL);
+       strreplace(reboot_cmd, ' ', '-');

        reboot = container_of(this, struct reboot_mode_driver, 
reboot_notifier);
-       magic = get_reboot_mode_magic(reboot, cmd);
+       magic = get_reboot_mode_magic(reboot, reboot_cmd);
        if (magic)
                reboot->write(reboot, magic);

> > [1]:
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/md/dm-verity-target.c?h=v5.5#n255
> >
> > Signed-off-by: Elliot Berman <eberman@xxxxxxxxxxxxxx>
> > ---
> >   .../devicetree/bindings/power/reset/reboot-mode.yaml    | 17 +++++++++++++++++
> >   1 file changed, 17 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/power/reset/reboot-mode.yaml b/Documentation/devicetree/bindings/power/reset/reboot-mode.yaml
> > index a6c9102..4ea6b33 100644
> > --- a/Documentation/devicetree/bindings/power/reset/reboot-mode.yaml
> > +++ b/Documentation/devicetree/bindings/power/reset/reboot-mode.yaml
> > @@ -19,6 +19,9 @@ description: |
> >     the bootloader what to do when the system reboots, and should be named
> >     as mode-xxx = <magic> (xxx is mode name, magic should be a non-zero value).
> >   
> > +  reboot-mode-magic and reboot-mode-names may be used in addition/instead of
> > +  mode-xxx style.
>
> It should be either/or in my opinion, not both.

OK, I can fix in the next patch.

> > +
> >     For example, modes common Android platform are:
> >       - normal: Normal reboot mode, system reboot with command "reboot".
> >       - recovery: Android Recovery mode, it is a mode to format the device or update a new image.
> > @@ -32,6 +35,14 @@ properties:
> >         description: |
> >           Default value to set on a reboot if no command was provided.
> >   
> > +  reboot-mode-names:
> > +    $ref: /schemas/types.yaml#/definitions/string-array
> > +    description: List of reboot commands, paired with reboot-mode-magic by index
> > +
> > +  reboot-mode-magic:
>
> 'reboot-modes' would align with normal patterns.

Ditto

> > +    $ref: /schemas/types.yaml#/definitions/uint32-array
> > +    description: List of reboot magic, paired with reboot-mode-names by index
> > +
> >   patternProperties:
> >     "^mode-.*$":
> >       $ref: /schemas/types.yaml#/definitions/uint32
> > @@ -44,4 +55,10 @@ examples:
> >         mode-bootloader = <2>;
> >         mode-loader = <3>;
> >       };
> > +
> > +  - |
> > +    reboot-mode {
> > +      reboot-mode-names = "normal", "bootloader", "dm-verity device corrupted";
> > +      reboot-mode-magic = <0x0>, <0x1>, <0xf>;
> > +    };
> >   ...
> > --
> > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> > a Linux Foundation Collaborative Project