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>
1 file changed