Re: [PATCH v2] of: Support CONFIG_CMDLINE_EXTEND config option

From: John Stultz
Date: Thu Jul 10 2014 - 03:33:36 EST


On Fri, Jan 13, 2012 at 11:15 PM, Doug Anderson <dianders@xxxxxxxxxxxx> wrote:
> The old logic assumes CMDLINE_FROM_BOOTLOADER vs. CMDLINE_FORCE and
> ignores CMDLINE_EXTEND. Here's the old logic:
>
> - CONFIG_CMDLINE_FORCE=true
> CONFIG_CMDLINE
> - dt bootargs=non-empty:
> dt bootargs
> - dt bootargs=empty, @data is non-empty string
> @data is left unchanged
> - dt bootargs=empty, @data is empty string
> CONFIG_CMDLINE (or "" if that's not defined)
>
> The new logic is now documented in of_fdt.h and is copied here for
> reference:
>
> - CONFIG_CMDLINE_FORCE=true
> CONFIG_CMDLINE
> - CONFIG_CMDLINE_EXTEND=true, @data is non-empty string
> @data + dt bootargs (even if dt bootargs are empty)
> - CONFIG_CMDLINE_EXTEND=true, @data is empty string
> CONFIG_CMDLINE + dt bootargs (even if dt bootargs are empty)
> - CMDLINE_FROM_BOOTLOADER=true, dt bootargs=non-empty:
> dt bootargs
> - CMDLINE_FROM_BOOTLOADER=true, dt bootargs=empty, @data is non-empty string
> @data is left unchanged
> - CMDLINE_FROM_BOOTLOADER=true, dt bootargs=empty, @data is empty string
> CONFIG_CMDLINE (or "" if that's not defined)
>
> Signed-off-by: Doug Anderson <dianders@xxxxxxxxxxxx>
> CC: devicetree-discuss@xxxxxxxxxxxxxxxx
> CC: Grant Likely <grant.likely@xxxxxxxxxxxx>
> CC: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
> CC: Rob Herring <rob.herring@xxxxxxxxxxx>
> ---
> I didn't hear a response from Ben about whether he was OK with
> my proposal for how CONFIG_CMDLINE_EXTEND should behave with
> a non-empty @data, so sending out code that implements my
> interpretation. Hopefully this looks OK.
>
> Changes in v2:
> - Removed broken fix for the case when there is no "chosen" attribute.
> - Changed CONFIG_CMDLINE_EXTEND behavior when @data is a non-empty string.

In reviewing some of the random patches in the Android AOSP common.git
tree, I noticed this one, and found this discussion which petered out
without resolution. Were there any objections still, or did this just
slip through the cracks?

Note, there's also this follow-on fix from Colin, which probably
should be included if the parent patch is merged:
https://android.googlesource.com/kernel/common.git/+/a2acc58bc7460a03627f20842a7169d7a1328299

thanks
-john
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/