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Groups > linux.kernel > #1403367
| From | Ming Lei <ming.lei@canonical.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH] tty: vt: Fix soft lockup in fbcon cursor blink timer. |
| Date | 2016-05-19 02:30 +0200 |
| Message-ID | <rAk0F-PE-3@gated-at.bofh.it> (permalink) |
| References | <rzSe5-8cx-5@gated-at.bofh.it> <rzU6e-W9-17@gated-at.bofh.it> <rzXQu-3gO-9@gated-at.bofh.it> <rAgq6-6Tl-7@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Thu, May 19, 2016 at 4:24 AM, Scot Doyle <lkml14@scotdoyle.com> wrote: > On Wed, 18 May 2016, Ming Lei wrote: >> On Wed, May 18, 2016 at 4:49 AM, Pavel Machek <pavel@ucw.cz> wrote: >> > On Tue 2016-05-17 11:41:04, David Daney wrote: >> >> From: David Daney <david.daney@cavium.com> >> >> >> >> 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: David Daney <david.daney@cavium.com> >> >> Cc: stable@vger.kernel.org >> > >> > Acked-by: Pavel Machek <pavel@ucw.cz> >> >> Tested-by: Ming Lei <ming.lei@canonical.com> >> >> Thanks David and Pavel for making it work! >> >> > >> > (And it is amazing how many problems configurable blink speed caused). >> > >> > Thanks! >> > Pavel >> > > > > Dann, Ming and David, thank you so much for all of your effort. > > There were three other reports in the past year, each leading to their own > patch, of boot lockups occuring when the cursor flash timer was set using > an ops->cur_blink_jiffies value of 0. I plan to propose a patch within > the next day that will prevent this for all code paths. Given this issue caues system unusable, I suggest to merge David's oneline patch first, then you can think and try to figure out 'perfect' solution for addressing all this kind of reports from last year. Does it make sense? Thanks, Ming
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[PATCH] tty: vt: Fix soft lockup in fbcon cursor blink timer. David Daney <ddaney.cavm@gmail.com> - 2016-05-17 20:50 +0200
Re: [PATCH] tty: vt: Fix soft lockup in fbcon cursor blink timer. Pavel Machek <pavel@ucw.cz> - 2016-05-17 22:50 +0200
Re: [PATCH] tty: vt: Fix soft lockup in fbcon cursor blink timer. Ming Lei <ming.lei@canonical.com> - 2016-05-18 02:50 +0200
Re: [PATCH] tty: vt: Fix soft lockup in fbcon cursor blink timer. Scot Doyle <lkml14@scotdoyle.com> - 2016-05-18 22:40 +0200
Re: [PATCH] tty: vt: Fix soft lockup in fbcon cursor blink timer. Ming Lei <ming.lei@canonical.com> - 2016-05-19 02:30 +0200
Re: [PATCH] tty: vt: Fix soft lockup in fbcon cursor blink timer. Pavel Machek <pavel@ucw.cz> - 2016-05-19 09:10 +0200
[PATCH] fbcon: use default if cursor blink interval is not valid Scot Doyle <lkml14@scotdoyle.com> - 2016-05-19 06:30 +0200
Re: [PATCH] fbcon: use default if cursor blink interval is not valid Jeremy Kerr <jk@ozlabs.org> - 2016-05-19 09:30 +0200
Re: [PATCH] fbcon: use default if cursor blink interval is not valid Ming Lei <ming.lei@canonical.com> - 2016-05-19 10:40 +0200
Re: [PATCH] fbcon: use default if cursor blink interval is not valid Pavel Machek <pavel@ucw.cz> - 2016-05-19 11:10 +0200
Re: [PATCH] fbcon: use default if cursor blink interval is not valid Scot Doyle <lkml14@scotdoyle.com> - 2016-05-19 16:30 +0200
Re: [PATCH] fbcon: use default if cursor blink interval is not valid Ming Lei <ming.lei@canonical.com> - 2016-05-19 17:40 +0200
Re: [PATCH] fbcon: use default if cursor blink interval is not valid Scot Doyle <lkml14@scotdoyle.com> - 2016-05-20 00:30 +0200
[PATCH] fbcon: warn on invalid cursor blink intervals Scot Doyle <lkml14@scotdoyle.com> - 2016-05-20 00:40 +0200
Re: [PATCH] fbcon: warn on invalid cursor blink intervals Jeremy Kerr <jk@ozlabs.org> - 2016-05-20 03:30 +0200
Re: [PATCH] fbcon: warn on invalid cursor blink intervals Ming Lei <ming.lei@canonical.com> - 2016-05-20 04:20 +0200
Re: [PATCH] fbcon: warn on invalid cursor blink intervals Jeremy Kerr <jk@ozlabs.org> - 2016-05-20 04:30 +0200
Re: [PATCH] fbcon: warn on invalid cursor blink intervals Ming Lei <ming.lei@canonical.com> - 2016-05-20 04:50 +0200
Re: [PATCH] fbcon: warn on invalid cursor blink intervals Jeremy Kerr <jk@ozlabs.org> - 2016-05-20 07:10 +0200
Re: [PATCH] fbcon: warn on invalid cursor blink intervals Scot Doyle <lkml14@scotdoyle.com> - 2016-05-20 18:30 +0200
Re: [PATCH] fbcon: warn on invalid cursor blink intervals Scot Doyle <lkml14@scotdoyle.com> - 2016-05-24 03:30 +0200
Re: [PATCH] fbcon: warn on invalid cursor blink intervals Henrique de Moraes Holschuh <hmh@hmh.eng.br> - 2016-05-28 13:50 +0200
Re: [PATCH] fbcon: warn on invalid cursor blink intervals Henrique de Moraes Holschuh <hmh@hmh.eng.br> - 2016-05-28 13:50 +0200
Re: [PATCH] tty: vt: Fix soft lockup in fbcon cursor blink timer. Scot Doyle <lkml14@scotdoyle.com> - 2016-05-20 00:40 +0200
Re: [PATCH] tty: vt: Fix soft lockup in fbcon cursor blink timer. Henrique de Moraes Holschuh <hmh@hmh.eng.br> - 2016-05-28 13:50 +0200
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