Messages in this thread |  | | Date | Mon, 11 Nov 2013 15:59:27 +0200 | From | Tomi Valkeinen <> | Subject | Re: [RESEND PATCH 1/2] fb: reorder the lock sequence to fix potential dead lock |
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On 2013-11-05 12:00, Gu Zheng wrote: > Following commits: > 50e244cc79 fb: rework locking to fix lock ordering on takeover > e93a9a8687 fb: Yet another band-aid for fixing lockdep mess > 054430e773 fbcon: fix locking harder > reworked locking to fix related lock ordering on takeover, and introduced console_lock > into fbmem, but it seems that the new lock sequence(fb_info->lock ---> console_lock) > is against with the one in console_callback(console_lock ---> fb_info->lock), and leads to > a potential dead lock as following:
<snip>
> so we reorder the lock sequence the same as it in console_callback() to > avoid this issue. And following Tomi's suggestion, fix these similar > issues all in fb subsystem. > > Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com> > --- > drivers/video/fbmem.c | 50 ++++++++++++++++++++++++------------- > drivers/video/fbsysfs.c | 19 ++++++++++---- > drivers/video/sh_mobile_lcdcfb.c | 10 ++++--- > 3 files changed, 51 insertions(+), 28 deletions(-)
I'll apply this for 3.13. It's a bit difficult to verify if the locking is now correct, but looks fine to me. And we can revert this easily if things break badly.
Tomi
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