Subject: [PATCH] Fix platform_driver emulation for kernels <= 2.6.14

The platform_driver_register() substitute in alsa-driver-1.0.10 sets
drv->driver.probe and drv->driver.remove functions without checking for
non-NULL drv->probe and drv->remove; snd_platform_driver_probe() and
snd_platform_driver_remove() also do not check for NULL in those fields.
However, snd_generic_driver has NULL ->probe and ->remove functions,
therefore attempts to use it on kernels <= 2.6.14 lead to oopses.

This patch changes platform_driver_register() provided by alsa-driver
for old kernels to match the implementation in post-2.6.14 kernels,
which checks for NULL ->probe and ->remove functions.

Signed-off-by: Sergey Vlasov <vsu@altlinux.ru>

--- alsa-driver-1.0.10/include/platform_device_compat.h.alt-platform_device_compat	2005-11-14 17:42:27 +0300
+++ alsa-driver-1.0.10/include/platform_device_compat.h	2005-12-03 23:01:26 +0300
@@ -61,8 +61,10 @@
 static inline int platform_driver_register(struct platform_driver *drv)
 {
 	drv->driver.bus = &platform_bus_type;
-	drv->driver.probe = snd_platform_driver_probe;
-	drv->driver.remove = snd_platform_driver_remove;
+	if (drv->probe)
+		drv->driver.probe = snd_platform_driver_probe;
+	if (drv->remove)
+		drv->driver.remove = snd_platform_driver_remove;
 	if (drv->suspend)
 		drv->driver.suspend = snd_platform_driver_suspend;
 	if (drv->resume)