Re: [PATCH v2 3/3] Add sixaxis plugin: USB pairing and LEDs settings

On Sat, 07 May 2011 17:57:07 +0100
Bastien Nocera [off-list ref] wrote:

quoted

On Sat, 2011-05-07 at 01:14 +0200, Antonio Ospite wrote:

quoted

On Fri, 06 May 2011 02:14:38 +0100
Bastien Nocera [off-list ref] wrote:

quoted

On Fri, 2011-02-25 at 11:04 +0100, Antonio Ospite wrote:

quoted

+                       [AC_LANG_PROGRAM([[
+                               #include <sys/ioctl.h>
+                               #include <linux/hidraw.h>
+                               #if ! (defined(HIDIOCSFEATURE) &&
defined(HIDIOCGFEATURE))
+                               #error "HIDIOCSFEATURE and
HIDIOCGFEATURE are required (linux-libc-dev >= 2.6.3x)"
+                               #endif
+                               ]], 

The only part of the patch I have a problem with is this one.

I'd rather the code had:
#ifndef HIDIOCSFEATURE
#define HIDIOCSFEATURE bleh
#endif

[...]

quoted

Again, it's not compiling against older kernels. but compiling against
older kernel headers, which is a wildly different thing.

I'd like the plugin to be enabled, even if building with older kernel
headers, as those have no relation to the capabilities of the running
kernel.

It would also make the whole thing easier to test (just install a newer
kernel with the patches merged in, and voila, working sisaxis pairing).

Bastien, I'd fulfill your request on the lines of the following
WIP patch, the intent is to make the plugin compile unconditionally
still mentioning the soft dependency on 2.6.39-rc1.
I could have set HAVE_HIDIOCxFEATURE in acinclude.m4 and checked for
that in sixaxis.c in place of the explicit ifdefs, what is the common
practice about that?

I still have to take care of the runtime check when running on older
kernels.

Regards,
   Antonio

diff --git a/acinclude.m4 b/acinclude.m4
index 901bb4d..e3e0fdd 100644
--- a/acinclude.m4
+++ b/acinclude.m4

@@ -167,12 +167,12 @@ AC_DEFUN([AC_PATH_SIXAXIS], [
 			)],[
 				ac_cv_have_HIDIOCxFEATURE=yes
 			],[
-				ac_cv_have_HIDIOCxFEATURE="no, get linux-libc-dev >= 2.6.39-rc1"
+				ac_cv_have_HIDIOCxFEATURE="no, emulating linux-libc-dev >= 2.6.39-rc1"
 			]
 		)]
 	)
 
-	if ( test "${udev_found}" = "yes" && test "${ac_cv_have_HIDIOCxFEATURE}" = "yes" ); then
+	if ( test "${udev_found}" = "yes" ); then
 		sixaxis_plugin_deps_found=yes
 	fi
 ])

diff --git a/plugins/sixaxis.c b/plugins/sixaxis.c
index 49aad25..fc12878 100644
--- a/plugins/sixaxis.c
+++ b/plugins/sixaxis.c

@@ -58,6 +58,16 @@
 #include "storage.h"
 #include "sdp_lib.h"
 
+/* Fallback definitions to compile with older headers */
+#ifndef HIDIOCGFEATURE
+#define HIDIOCGFEATURE(len)    _IOC(_IOC_WRITE|_IOC_READ, 'H', 0x07, len)
+#endif
+
+#ifndef HIDIOCSFEATURE
+#define HIDIOCSFEATURE(len)    _IOC(_IOC_WRITE|_IOC_READ, 'H', 0x06, len)
+#endif