[PATCH] lz4c: shut up lz4c output

[PATCH] lz4c: shut up lz4c output

[Arnd Bergmann]

When KERNEL_LZ4 is set, we always get an output even when building
with 'make -s':

    *** LZ4 Compression CLI , by Yann Collet (May 31 2013) ***
    ! Generating compressed LZ4 using Legacy format (deprecated !) !
    Using stdin for input
    Using stdout for output
    Compressed 11213376 bytes into 4555781 bytes ==> 40.63%
    Done in 0.63 s ==> 16.97 MB/s

The output is not helpful in the context of building the kernel,
so this patch hides the stdout output of the lz4 binary completely.

We could also try to not hide the output when building without '-s',
but I could not come up with any use for that.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 scripts/Makefile.lib | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 31d7a73c35ce..5ab935aed8ad 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -347,7 +347,7 @@ cmd_lzo = (cat $(filter-out FORCE,$^) | \
 
 quiet_cmd_lz4 = LZ4     $@
 cmd_lz4 = (cat $(filter-out FORCE,$^) | \
-	lz4c -l -c1 stdin stdout && $(call size_append, $(filter-out FORCE,$^))) > $@ || \
+	lz4c -l -c1 stdin stdout && $(call size_append, $(filter-out FORCE,$^))) > $@ 2>&1 || \
 	(rm -f $@ ; false)
 
 # U-Boot mkimage
-- 
2.7.0

Re: [PATCH] lz4c: shut up lz4c output

[Michal Marek]

On 2016-02-29 13:40, Arnd Bergmann wrote:
> When KERNEL_LZ4 is set, we always get an output even when building
> with 'make -s':
> 
>     *** LZ4 Compression CLI , by Yann Collet (May 31 2013) ***
>     ! Generating compressed LZ4 using Legacy format (deprecated !) !
>     Using stdin for input
>     Using stdout for output
>     Compressed 11213376 bytes into 4555781 bytes ==> 40.63%
>     Done in 0.63 s ==> 16.97 MB/s
> 
> The output is not helpful in the context of building the kernel,
> so this patch hides the stdout output of the lz4 binary completely.

> -	lz4c -l -c1 stdin stdout && $(call size_append, $(filter-out FORCE,$^))) > $@ || \
> +	lz4c -l -c1 stdin stdout && $(call size_append, $(filter-out FORCE,$^))) > $@ 2>&1 || \
>  	(rm -f $@ ; false)

Hi Arnd,

this redirection does not hide it, but rather includes it in the
compressed image file.

BTW, my copy of lz4c only displays this warning with -v.

Michal

Re: [PATCH] lz4c: shut up lz4c output

[Arnd Bergmann]

On Monday 29 February 2016 13:58:13 Michal Marek wrote:
> On 2016-02-29 13:40, Arnd Bergmann wrote:
> > When KERNEL_LZ4 is set, we always get an output even when building
> > with 'make -s':
> > 
> >     *** LZ4 Compression CLI , by Yann Collet (May 31 2013) ***
> >     ! Generating compressed LZ4 using Legacy format (deprecated !) !
> >     Using stdin for input
> >     Using stdout for output
> >     Compressed 11213376 bytes into 4555781 bytes ==> 40.63%
> >     Done in 0.63 s ==> 16.97 MB/s
> > 
> > The output is not helpful in the context of building the kernel,
> > so this patch hides the stdout output of the lz4 binary completely.
> 
> > -     lz4c -l -c1 stdin stdout && $(call size_append, $(filter-out FORCE,$^))) > $@ || \
> > +     lz4c -l -c1 stdin stdout && $(call size_append, $(filter-out FORCE,$^))) > $@ 2>&1 || \
> >       (rm -f $@ ; false)
> 
> Hi Arnd,
> 
> this redirection does not hide it, but rather includes it in the
> compressed image file.

Oops, you are right. I was cleaning out some older patches I had in my
queue and hadn't realized it was completely botched this way.

> BTW, my copy of lz4c only displays this warning with -v.

I've updated my copy of lz4c now and can confirm that the output
is completely gone (without -v). I won't follow up with a fixed version
then, as the problem is already solved elsewhere.

	Arnd