Re: [GIT PULL for v4.6-rc1] media updates

From: Mauro Carvalho Chehab
Date: Wed May 04 2016 - 17:51:22 EST

Em Wed, 4 May 2016 13:49:52 -0700
Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> escreveu:

> On Wed, May 4, 2016 at 12:28 PM, Stefan Lippers-Hollmann <s.l-h@xxxxxx> wrote:
> >
> > --- a/drivers/media/media-device.c
> > +++ b/drivers/media/media-device.c
> > @@ -875,7 +875,7 @@ void __media_device_usb_init(struct medi
> > const char *board_name,
> > const char *driver_name)
> > {
> > -#ifdef CONFIG_USB
> > +#if defined(CONFIG_USB) || defined(CONFIG_USB_MODULE)
> Ok, that should be fine. Can you verify that it builds and works even
> if USB isn't compiled in, but the media core code is?
> IOW, can you test the
> case? Judging by your oops stack trace, I think you currently have

I think we could use, instead:


This macro is defined as:
* IS_REACHABLE(CONFIG_FOO) evaluates to 1 if the currently compiled
* code can call a function defined in code compiled based on CONFIG_FOO.
* This is similar to IS_ENABLED(), but returns false when invoked from
* built-in code when CONFIG_FOO is set to 'm'.
#define IS_REACHABLE(option) (config_enabled(option) || \
(config_enabled(option##_MODULE) && config_enabled(MODULE)))

And we use it already on other places where we have dependencies
like that.

Btw, there are also some helper function there to initialize
for PCI devices.

> Also, I do wonder if we should move that #if to _outside_ the
> function. Because inside the function, things will compile but
> silently not work (like you found), if it is ever mis-used. Outside
> that function, you'll get link-errors if you try to misuse that
> function.

Yeah, that makes sense. This function is a helper function that
it is used only when CONFIG_USB.

The following (untested) patch should do the work.


Could you please test the enclosed patch?


[media] media-device: fix builds when USB or PCI is compiled as module

Just checking ifdef CONFIG_USB is not enough, if the USB is compiled
as module. The same applies to PCI.

Compile-tested only.

So, change the logic to use, instead, IS_REACHABLE.

Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx>

diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
index b84825715f98..8c1f80ff33e3 100644
--- a/drivers/media/media-device.c
+++ b/drivers/media/media-device.c
@@ -842,11 +842,11 @@ struct media_device *media_device_find_devres(struct device *dev)

void media_device_pci_init(struct media_device *mdev,
struct pci_dev *pci_dev,
const char *name)
-#ifdef CONFIG_PCI
mdev->dev = &pci_dev->dev;

if (name)
@@ -862,16 +862,16 @@ void media_device_pci_init(struct media_device *mdev,
mdev->driver_version = LINUX_VERSION_CODE;


void __media_device_usb_init(struct media_device *mdev,
struct usb_device *udev,
const char *board_name,
const char *driver_name)
-#ifdef CONFIG_USB
mdev->dev = &udev->dev;

if (driver_name)
@@ -891,9 +891,9 @@ void __media_device_usb_init(struct media_device *mdev,
mdev->driver_version = LINUX_VERSION_CODE;