On Thu, 19 May 2016, David Daney wrote: > On 05/18/2016 09:21 PM, Scot Doyle wrote: > > Two current [1] and three previous [2] systems locked during boot > > because the cursor flash timer was set using an ops->cur_blink_jiffies > > value of 0. Previous patches attempted to solve the problem by moving > > variable initialization earlier in the setup sequence [2]. > > > > Use the normal cursor blink default interval of 200 ms if > > ops->cur_blink_jiffies is not in the range specified in commit > > bd63364caa8d. Since invalid values are not used, specific system > > initialization timings should not cause lockups. > > > > This patch just papers over the problem that you yourself introduced in commit > bd63364caa8d ("vt: add cursor blink interval escape sequence"). > > As you know, I have a patch that fixes the problem at the source: > https://lkml.org/lkml/2016/5/17/455 > > I don't like the idea of silently ignoring bad values passed in from other > code (drivers/tty/vt/vt.c), and much less doing the check for bad values each > time the timer expires rather than just once, where the bad value is first > introduced. > > I think it would be preferable to WARN() at the site the bad value is > introduced, so that we can easily find the real source of the problem. > Initialize cur_blink_jiffies to a sane default value, then if something > attempts to set it to a value that would cause soft lockup, WARN and refuse to > change it. I agree this approach would be cleaner and am willing to give it a try by submitting an alternative patch and ack'ing yours. Thanks for taking the time to critique my proposal. -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html