diff options
| author | Jean-Philippe Brucker <jean-philippe.brucker@arm.com> | 2016-02-15 18:41:33 +0000 | 
|---|---|---|
| committer | Tomi Valkeinen <tomi.valkeinen@ti.com> | 2016-02-26 13:19:55 +0200 | 
| commit | a1e533ec07d583d01349ef13c0c965b8633e1b91 (patch) | |
| tree | e894dd45f130d60347d68993a4ce15c51db81756 | |
| parent | 81f70ba233d5f660e1ea5fe23260ee323af5d53a (diff) | |
fbcon: set a default value to blink interval
Since commit 27a4c827c34ac4256a190cc9d24607f953c1c459
	fbcon: use the cursor blink interval provided by vt
two attempts have been made at fixing a possible hang caused by
cursor_timer_handler. That function registers a timer to be triggered at
"jiffies + fbcon_ops.cur_blink_jiffies".
A new case had been encountered during initialisation of clcd-pl11x:
    fbcon_fb_registered
    do_fbcon_takeover
    ->  do_register_con_driver
        fbcon_startup
    (A) add_cursor_timer (with cur_blink_jiffies = 0)
    ->  do_bind_con_driver
        visual_init
        fbcon_init
    (B) cur_blink_jiffies = msecs_to_jiffies(vc->vc_cur_blink_ms);
If we take an softirq anywhere between A and B (and we do),
cursor_timer_handler executes indefinitely.
Instead of patching all possible paths that lead to this case one at a
time, fix the issue at the source and initialise cur_blink_jiffies to
200ms when allocating fbcon_ops. This was its default value before
aforesaid commit. fbcon_cursor or fbcon_init will refine this value
downstream.
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Cc: <stable@vger.kernel.org> # v4.2
Tested-by: Scot Doyle <lkml14@scotdoyle.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
| -rw-r--r-- | drivers/video/console/fbcon.c | 2 | 
1 files changed, 2 insertions, 0 deletions
| diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c index 92f394927f24..6e92917ba77a 100644 --- a/drivers/video/console/fbcon.c +++ b/drivers/video/console/fbcon.c @@ -709,6 +709,7 @@ static int con2fb_acquire_newinfo(struct vc_data *vc, struct fb_info *info,  	}  	if (!err) { +		ops->cur_blink_jiffies = HZ / 5;  		info->fbcon_par = ops;  		if (vc) @@ -956,6 +957,7 @@ static const char *fbcon_startup(void)  	ops->currcon = -1;  	ops->graphics = 1;  	ops->cur_rotate = -1; +	ops->cur_blink_jiffies = HZ / 5;  	info->fbcon_par = ops;  	p->con_rotate = initial_rotation;  	set_blitting_type(vc, info); | 
