Re: [PATCH V5 1/3] dt-bindings: mtd: document linux,part-probe property

Brian Norris
2017-04-19T20:37:31Z

Hi,

On Mon, Apr 17, 2017 at 09:47:44PM +0200, Rafał Miłecki wrote:
> From: Rafał Miłecki <rafal@milecki.pl>
>
> Support for this property has been introduced in 2010 with commit
> 9d5da3a9b849 ("mtd: extend physmap_of to let the device tree specify the
> parition probe") but it was never documented. Fix this by adding a
> proper description and example.
>
> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
> Acked-by: Rob Herring <robh@kernel.org>
> Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> ---
> Documentation/devicetree/bindings/mtd/common.txt | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/mtd/common.txt b/Documentation/devicetree/bindings/mtd/common.txt
> index fc068b923d7a..1ada70e718b2 100644
> --- a/Documentation/devicetree/bindings/mtd/common.txt
> +++ b/Documentation/devicetree/bindings/mtd/common.txt
> @@ -6,10 +6,17 @@ Optional properties:
> controller based name) in order to ease flash device identification
> and/or describe what they are used for.
>
> +- linux,part-probe: if present, this property should contain a list of strings
> + with partition probes to be used for the flash device. A role of partition
> + probe (parser) is to read/construct partition table and register found
> + partitions. Getting partition table may be platform or device specific so
> + various devices may use various Linux drivers for this purpose.

Have you reviewed the old threads about this? I thought I already
discouraged extending this binding to be generic. Particularly, we do
*not* want to codify things like 'linux,part-probe = "bcm47xxpart"',
which doesn't follow any accepted practice about naming. And you've also
failed to document any actual strings to put here, which hides the fact
that you're opening a can of worms.

Piece of a previous thread:
http://lists.infradead.org/pipermail/linux-mtd/2015-October/062613.html
[PATCH] mtd: document linux-specific partition parser DT binding

I attempted to resolve that here, but never made time to address the few
not-so-constructive comments I received:

https://mail-archive.com/linux-kernel@vger.kernel.org/msg1035539.html
[RFC PATCH 0/7] mtd: partitions: add of_match_table support

I'd still prefer that approach to supporting this shortcut for all MTDs.

Brian

> +
> Example:
>
> flash@0 {
> label = "System-firmware";
> + linux,part-probe = "cmdlinepart", "ofpart";
>
> /* flash type specific properties */
> };
> --
> 2.11.0
>