From 68dd25deda2f7995f127abd206596c78d1fb4c09 Mon Sep 17 00:00:00 2001 From: David Daney Date: Tue, 17 May 2016 11:41:04 -0700 Subject: [PATCH] tty: vt: Fix soft lockup in fbcon cursor blink timer. commit 1b45996d2ebf9680ccd0db875fc668aa025f40fd upstream. We are getting somewhat random soft lockups with this signature: [ 86.992215] [] el1_irq+0xa0/0x10c [ 86.997082] [] cursor_timer_handler+0x30/0x54 [ 87.002991] [] call_timer_fn+0x54/0x1a8 [ 87.008378] [] run_timer_softirq+0x1c4/0x2bc [ 87.014200] [] __do_softirq+0x114/0x344 [ 87.019590] [] irq_exit+0x74/0x98 [ 87.024458] [] __handle_domain_irq+0x98/0xfc [ 87.030278] [] gic_handle_irq+0x94/0x190 This is caused by the vt visual_init() function calling into fbcon_init() with a vc_cur_blink_ms value of zero. This is a transient condition, as it is later set to a non-zero value. But, if the timer happens to expire while the blink rate is zero, it goes into an endless loop, and we get soft lockup. The fix is to initialize vc_cur_blink_ms before calling the con_init() function. Signed-off-by: David Daney Acked-by: Pavel Machek Tested-by: Ming Lei Acked-by: Scot Doyle Tested-by: Henrique de Moraes Holschuh Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman --- drivers/tty/vt/vt.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c index bd523adb96433..e9e29ded3f30c 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -750,6 +750,7 @@ static void visual_init(struct vc_data *vc, int num, int init) vc->vc_complement_mask = 0; vc->vc_can_do_color = 0; vc->vc_panic_force_write = false; + vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS; vc->vc_sw->con_init(vc, init); if (!vc->vc_complement_mask) vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800; -- 2.47.2