[PATCH 5.16 1027/1039] scripts/dtc: dtx_diff: remove broken example from help text

From: Greg Kroah-Hartman
Date: Mon Jan 24 2022 - 21:00:29 EST


From: Matthias Schiffer <matthias.schiffer@xxxxxxxxxxxxxxx>

commit d8adf5b92a9d2205620874d498c39923ecea8749 upstream.

dtx_diff suggests to use <(...) syntax to pipe two inputs into it, but
this has never worked: The /proc/self/fds/... paths passed by the shell
will fail the `[ -f "${dtx}" ] && [ -r "${dtx}" ]` check in compile_to_dts,
but even with this check removed, the function cannot work: hexdump will
eat up the DTB magic, making the subsequent dtc call fail, as a pipe
cannot be rewound.

Simply remove this broken example, as there is already an alternative one
that works fine.

Fixes: 10eadc253ddf ("dtc: create tool to diff device trees")
Signed-off-by: Matthias Schiffer <matthias.schiffer@xxxxxxxxxxxxxxx>
Reviewed-by: Frank Rowand <frank.rowand@xxxxxxxx>
Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220113081918.10387-1-matthias.schiffer@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
scripts/dtc/dtx_diff | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)

--- a/scripts/dtc/dtx_diff
+++ b/scripts/dtc/dtx_diff
@@ -59,12 +59,8 @@ Otherwise DTx is treated as a dts source
or '/include/' to be processed.

If DTx_1 and DTx_2 are in different architectures, then this script
- may not work since \${ARCH} is part of the include path. Two possible
- workarounds:
-
- `basename $0` \\
- <(ARCH=arch_of_dtx_1 `basename $0` DTx_1) \\
- <(ARCH=arch_of_dtx_2 `basename $0` DTx_2)
+ may not work since \${ARCH} is part of the include path. The following
+ workaround can be used:

`basename $0` ARCH=arch_of_dtx_1 DTx_1 >tmp_dtx_1.dts
`basename $0` ARCH=arch_of_dtx_2 DTx_2 >tmp_dtx_2.dts