Re: [PATCH 10/12] [media] move i2c files into drivers/media/i2c

[Mauro Carvalho Chehab <mchehab@redhat.com>]

Em 24-08-2012 20:44, Sylwester Nawrocki escreveu:
> From: Sylwester Nawrocki <sylvester.nawrocki@gmail.com>
> Date: Sat, 25 Aug 2012 01:23:14 +0200
> Subject: [PATCH] [media] Fix link order of the V4L2 bridge and I2C modules
> 
> All I2C modules must be linked first to ensure proper module
> initialization order. With platform devices linked before I2C
> modules I2C subdev registration fails as the subdev drivers
> are not yet initialized during bridge driver's probing.
> 
> This fixes regression introduced with commmit cb7a01ac324bf2ee2,
> "[media] move i2c files into drivers/media/i2c".
> 
> Signed-off-by: Sylwester Nawrocki <sylvester.nawrocki@gmail.com>
> ---
>  drivers/media/Makefile |    7 ++++---
>  1 files changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/Makefile b/drivers/media/Makefile
> index b0b0193..92a8bcf 100644
> --- a/drivers/media/Makefile
> +++ b/drivers/media/Makefile
> @@ -8,8 +8,9 @@ ifeq ($(CONFIG_MEDIA_CONTROLLER),y)
>    obj-$(CONFIG_MEDIA_SUPPORT) += media.o
>  endif
>  
> -obj-y += tuners/ common/ rc/ platform/
> -obj-y += i2c/ pci/ usb/ mmc/ firewire/ parport/
> +obj-$(CONFIG_VIDEO_DEV) += v4l2-core/
> +obj-y += common/ rc/ i2c/
> +obj-y += tuners/ platform/ pci/ usb/ mmc/ firewire/ parport/
>  
> -obj-$(CONFIG_VIDEO_DEV) += radio/ v4l2-core/
> +obj-$(CONFIG_VIDEO_DEV) += radio/
>  obj-$(CONFIG_DVB_CORE)  += dvb-core/ dvb-frontends/
> -- 1.7.4.1

Hmm... This change seems incomplete on my eyes: tuners and dvb-frontends
are also I2C drivers. So, while this fixes the issue for platform drivers,
other drivers will still suffer this issue, at least on drivers that doesn't
depend on drivers located outside the media subsystem[1]

[1] thankfully, staging compiles after media, so the drivers there
shouldn't be affected. Also, drivers that use alsa won't be affected, as
alsa core (with is compiled after media) uses subsys_initcall().

IMO, the correct fix is the one below. Could you please test it?

Regards,
Mauro

-

[media] Fix init order for I2C drivers

Based on a patch from Sylvester Nawrocki

This fixes regression introduced with commmit cb7a01ac324bf2ee2,
"[media] move i2c files into drivers/media/i2c".

The linked order affect what drivers will be initialized first, when
they're built-in at Kernel. While there are macros that allow changing
the init order, like subsys_initcall(), late_initcall() & friends,
when all drivers  linked belong to the same subsystem, it is easier
to change the order at the Makefile.

All I2C modules must be linked before any drivers that actually use it,
in order to ensure proper module initialization order.

Also, the core drivers should be initialized before the drivers that use
them.

This patch reorders the drivers init, in order to fulfill the above
requirements.

Reported-by: Sylwester Nawrocki <sylvester.nawrocki@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/Makefile b/drivers/media/Makefile
index b0b0193..620f275 100644
--- a/drivers/media/Makefile
+++ b/drivers/media/Makefile
@@ -4,12 +4,30 @@
 
 media-objs	:= media-device.o media-devnode.o media-entity.o
 
+#
+# I2C drivers should come before other drivers, otherwise they'll fail
+# when compiled as builtin drivers
+#
+obj-y += i2c/ tuners/
+obj-$(CONFIG_DVB_CORE)  += dvb-frontends/
+
+#
+# Now, let's link-in the media core
+#
 ifeq ($(CONFIG_MEDIA_CONTROLLER),y)
   obj-$(CONFIG_MEDIA_SUPPORT) += media.o
 endif
 
-obj-y += tuners/ common/ rc/ platform/
-obj-y += i2c/ pci/ usb/ mmc/ firewire/ parport/
+obj-$(CONFIG_VIDEO_DEV) += v4l2-core/
+obj-$(CONFIG_DVB_CORE)  += dvb-core/
+
+# There are both core and drivers at RC subtree - merge before drivers
+obj-y += rc/
+
+#
+# Finally, merge the drivers that require the core
+#
+
+obj-y += common/ platform/ pci/ usb/ mmc/ firewire/ parport/
+obj-$(CONFIG_VIDEO_DEV) += radio/
 
-obj-$(CONFIG_VIDEO_DEV) += radio/ v4l2-core/
-obj-$(CONFIG_DVB_CORE)  += dvb-core/ dvb-frontends/