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

On 8/25/2020 5:25 PM, Rob Herring wrote:

On Tue, Aug 18, 2020 at 11:54:14AM -0700, Elliot Berman wrote:

quoted

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);

quoted

[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 <redacted>
---
  .../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.

quoted

+
    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

quoted

+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    description: List of reboot magic, paired with reboot-mode-names by index
+
  patternProperties:
    "^mode-.*$":
      $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>;
+    };
  ...

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