Staging: udlfb: explicit dependencies and warnings

Specify Kconfig dependencies, and include warnings for building as a module

udlfb is dependent on FB_DEFERRED_IO, FB_SYS_*, and FB_MODE_HELPERS

Because many kernels do not include defio (which cannot be built
as a module), yet users want to be able to build udlfb as a module later,
udlfb has ifdefs and these dependency warnings to help udlfb build with or
without certain dependencies, but also print warnings for any lost function.

Even though this kind of flexibility isn't common, we've gotten feedback
from a significant portion of users that they were frustrated without it.

Signed-off-by: Bernie Thompson <bernie@plugable.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Bernie Thompson 2010-02-15 06:46:35 -08:00 committed by Greg Kroah-Hartman
parent 3e8f3d6fa6
commit dd8015f1c8
2 changed files with 24 additions and 4 deletions

View File

@ -1,8 +1,14 @@
config FB_UDL
tristate "Displaylink USB Framebuffer support"
depends on FB && USB
select FB_MODE_HELPERS
select FB_SYS_FILLRECT
select FB_SYS_COPYAREA
select FB_SYS_IMAGEBLIT
select FB_SYS_FOPS
select FB_DEFERRED_IO
---help---
This is an experimental driver for DisplayLink USB devices
that provides a framebuffer device. A normal framebuffer can
be used with this driver, or xorg can be run on the device
using it.
This is a kernel framebuffer driver for DisplayLink USB devices.
Supports fbdev clients like xf86-video-fbdev, kdrive, fbi, and
mplayer -vo fbdev. Supports all USB 2.0 era DisplayLink devices.
To compile as a module, choose M here: the module name is udlfb.

View File

@ -56,6 +56,20 @@ static struct usb_device_id id_table[] = {
};
MODULE_DEVICE_TABLE(usb, id_table);
#ifndef CONFIG_FB_DEFERRED_IO
#warning message "kernel FB_DEFFERRED_IO option to support generic fbdev apps"
#endif
#ifndef CONFIG_FB_SYS_IMAGEBLIT
#ifndef CONFIG_FB_SYS_IMAGEBLIT_MODULE
#warning message "FB_SYS_* in kernel or module option to support fb console"
#endif
#endif
#ifndef CONFIG_FB_MODE_HELPERS
#warning message "kernel FB_MODE_HELPERS required. Expect build break"
#endif
/* dlfb keeps a list of urbs for efficient bulk transfers */
static void dlfb_urb_completion(struct urb *urb);
static struct urb *dlfb_get_urb(struct dlfb_data *dev);