• David Daney's avatar
    tty: vt: Fix soft lockup in fbcon cursor blink timer. · 1b45996d
    David Daney authored
    We are getting somewhat random soft lockups with this signature:
    
    [   86.992215] [<fffffc00080935e0>] el1_irq+0xa0/0x10c
    [   86.997082] [<fffffc000841822c>] cursor_timer_handler+0x30/0x54
    [   87.002991] [<fffffc000810ec44>] call_timer_fn+0x54/0x1a8
    [   87.008378] [<fffffc000810ef88>] run_timer_softirq+0x1c4/0x2bc
    [   87.014200] [<fffffc000809077c>] __do_softirq+0x114/0x344
    [   87.019590] [<fffffc00080af45c>] irq_exit+0x74/0x98
    [   87.024458] [<fffffc00080fac20>] __handle_domain_irq+0x98/0xfc
    [   87.030278] [<fffffc000809056c>] 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: default avatarDavid Daney <david.daney@cavium.com>
    Cc: stable@vger.kernel.org
    Acked-by: default avatarPavel Machek <pavel@ucw.cz>
    Tested-by: default avatarMing Lei <ming.lei@canonical.com>
    Acked-by: default avatarScot Doyle <lkml14@scotdoyle.com>
    Tested-by: default avatarHenrique de Moraes Holschuh <hmh@hmh.eng.br>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    1b45996d
vt.c 103 KB