[PATCH] Add patch to allow compilation on versions < 3.5 with CONFIG_OF

[PATCH] Add patch to allow compilation on versions < 3.5 with CONFIG_OF

[Devin Heitmueller]

Support for Open Firmware was introduced in the V4L2 tree, but
it depends on features only found in 3.5+.  Add a patch to disable
the support for earlier kernels.

Tested on Ubuntu 10.04 with kernel 3.2.0-030200-generic (which has
CONFIG_OF enabled by default).

Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
---
 backports/backports.txt           |  1 +
 backports/v3.4_openfirmware.patch | 13 +++++++++++++
 2 files changed, 14 insertions(+)
 create mode 100644 backports/v3.4_openfirmware.patch

diff --git a/backports/backports.txt b/backports/backports.txt
index 281c263..08908e6 100644
--- a/backports/backports.txt
+++ b/backports/backports.txt
@@ -43,6 +43,7 @@ add v3.6_i2c_add_mux_adapter.patch
 
 [3.4.255]
 add v3.4_i2c_add_mux_adapter.patch
+add v3.4_openfirmware.patch
 
 [3.2.255]
 add v3.2_devnode_uses_mode_t.patch
diff --git a/backports/v3.4_openfirmware.patch b/backports/v3.4_openfirmware.patch
new file mode 100644
index 0000000..f0a8d36
--- /dev/null
+++ b/backports/v3.4_openfirmware.patch
@@ -0,0 +1,13 @@
+--- a/drivers/media/v4l2-core/v4l2-of.c	2014-06-11 17:05:02.000000000 -0700
++++ b/drivers/media/v4l2-core/v4l2-of.c	2014-06-11 17:05:34.000000000 -0700
+@@ -1,3 +1,5 @@
++/* Depends on symbols not present until kernel 3.5 */
++#if 0
+ /*
+  * V4L2 OF binding parsing library
+  *
+@@ -142,3 +144,4 @@
+ 	return 0;
+ }
+ EXPORT_SYMBOL(v4l2_of_parse_endpoint);
++#endif
-- 
1.9.1

Re: [PATCH] Add patch to allow compilation on versions < 3.5 with CONFIG_OF

[Hans Verkuil]

On 06/12/2014 05:45 PM, Devin Heitmueller wrote:
> Support for Open Firmware was introduced in the V4L2 tree, but
> it depends on features only found in 3.5+.  Add a patch to disable
> the support for earlier kernels.
> 
> Tested on Ubuntu 10.04 with kernel 3.2.0-030200-generic (which has
> CONFIG_OF enabled by default).

Doesn't this produce compiler warnings since the static v4l2_of_parse_*
functions are now never called?

I would patch v4l2-core/Makefile instead to just never compile v4l2-of.o.

Regards,

	Hans

> 
> Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
> ---
>  backports/backports.txt           |  1 +
>  backports/v3.4_openfirmware.patch | 13 +++++++++++++
>  2 files changed, 14 insertions(+)
>  create mode 100644 backports/v3.4_openfirmware.patch
> 
> diff --git a/backports/backports.txt b/backports/backports.txt
> index 281c263..08908e6 100644
> --- a/backports/backports.txt
> +++ b/backports/backports.txt
> @@ -43,6 +43,7 @@ add v3.6_i2c_add_mux_adapter.patch
>  
>  [3.4.255]
>  add v3.4_i2c_add_mux_adapter.patch
> +add v3.4_openfirmware.patch
>  
>  [3.2.255]
>  add v3.2_devnode_uses_mode_t.patch
> diff --git a/backports/v3.4_openfirmware.patch b/backports/v3.4_openfirmware.patch
> new file mode 100644
> index 0000000..f0a8d36
> --- /dev/null
> +++ b/backports/v3.4_openfirmware.patch
> @@ -0,0 +1,13 @@
> +--- a/drivers/media/v4l2-core/v4l2-of.c	2014-06-11 17:05:02.000000000 -0700
> ++++ b/drivers/media/v4l2-core/v4l2-of.c	2014-06-11 17:05:34.000000000 -0700
> +@@ -1,3 +1,5 @@
> ++/* Depends on symbols not present until kernel 3.5 */
> ++#if 0
> + /*
> +  * V4L2 OF binding parsing library
> +  *
> +@@ -142,3 +144,4 @@
> + 	return 0;
> + }
> + EXPORT_SYMBOL(v4l2_of_parse_endpoint);
> ++#endif
> 

Re: [PATCH] Add patch to allow compilation on versions < 3.5 with CONFIG_OF

[Devin Heitmueller]

> Doesn't this produce compiler warnings since the static v4l2_of_parse_*
> functions are now never called?

Those functions are inside the "#if 0", so the compiler never sees them.

> I would patch v4l2-core/Makefile instead to just never compile v4l2-of.o.

Because the final Makefile is generated by a script, I didn't think
you actually could address it at the "make prepare" phase.  That said,
now I see that I could have patched
linux/drivers/media/vl2-core/Makefile as you suggested.

I don't have time to regenerate/resubmit at this point.  Take the
patch if you want it, feel free to recreate the patch slightly
differently with no discernible benefit, or eventually I will get
around to it the next time I'm working on that tree.

Cheers,

Devin

-- 
Devin J. Heitmueller - Kernel Labs
http://www.kernellabs.com