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linux-next/drivers/video/console/dummycon.c
Daniel Vetter a4de05268e drm/i915: Kick out vga console
Touching the VGA resources on an IVB EFI machine causes hard hangs when
we then kick out the efifb. Ouch.

Apparently this also prevents unclaimed register errors on hsw and
hard machine hangs on my i855gm when trying to unbind fbcon.

Also, we want this to make I915_FBDEV=n safe.

v2: Rebase and pimp commit message.

v3: We also need to unregister the vga console, otherwise the unbind
of the fb console before module unload might resurrect it again.

v4: Ignore errors when the vga console is already unregistered - this
can happen when e.g. reloading i915.ko.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=67813
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: linux-fbdev@vger.kernel.org
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> (v1)
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Acked-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2014-06-09 21:03:47 +02:00

81 lines
1.8 KiB
C

/*
* linux/drivers/video/dummycon.c -- A dummy console driver
*
* To be used if there's no other console driver (e.g. for plain VGA text)
* available, usually until fbcon takes console over.
*/
#include <linux/types.h>
#include <linux/kdev_t.h>
#include <linux/console.h>
#include <linux/vt_kern.h>
#include <linux/screen_info.h>
#include <linux/init.h>
#include <linux/module.h>
/*
* Dummy console driver
*/
#if defined(__arm__)
#define DUMMY_COLUMNS screen_info.orig_video_cols
#define DUMMY_ROWS screen_info.orig_video_lines
#elif defined(__hppa__)
/* set by Kconfig. Use 80x25 for 640x480 and 160x64 for 1280x1024 */
#define DUMMY_COLUMNS CONFIG_DUMMY_CONSOLE_COLUMNS
#define DUMMY_ROWS CONFIG_DUMMY_CONSOLE_ROWS
#else
#define DUMMY_COLUMNS 80
#define DUMMY_ROWS 25
#endif
static const char *dummycon_startup(void)
{
return "dummy device";
}
static void dummycon_init(struct vc_data *vc, int init)
{
vc->vc_can_do_color = 1;
if (init) {
vc->vc_cols = DUMMY_COLUMNS;
vc->vc_rows = DUMMY_ROWS;
} else
vc_resize(vc, DUMMY_COLUMNS, DUMMY_ROWS);
}
static int dummycon_dummy(void)
{
return 0;
}
#define DUMMY (void *)dummycon_dummy
/*
* The console `switch' structure for the dummy console
*
* Most of the operations are dummies.
*/
const struct consw dummy_con = {
.owner = THIS_MODULE,
.con_startup = dummycon_startup,
.con_init = dummycon_init,
.con_deinit = DUMMY,
.con_clear = DUMMY,
.con_putc = DUMMY,
.con_putcs = DUMMY,
.con_cursor = DUMMY,
.con_scroll = DUMMY,
.con_bmove = DUMMY,
.con_switch = DUMMY,
.con_blank = DUMMY,
.con_font_set = DUMMY,
.con_font_get = DUMMY,
.con_font_default = DUMMY,
.con_font_copy = DUMMY,
.con_set_palette = DUMMY,
.con_scrolldelta = DUMMY,
};
EXPORT_SYMBOL_GPL(dummy_con);