On 09/12/2013 09:22 AM, johnflux wrote:
The following seems to be better:From d93c1e9761ff66365d658da7d8d0d33823aa946f Mon Sep 17 00:00:00 2001 From: John Tapsell<johnf...@gmail.com> Date: Thu, 12 Sep 2013 09:16:12 +0100 Subject: [PATCH] Fix deadlock between fb_info and console. Do not lock fb_info when calling sending the FB_EVENT_CONBLANK In fbmem.c, the semantics are that we acquire the lock_fb_info first, and then console_lock. However when fbcon.c fbcon_generic_blank() is called, the console lock could already be held. Locking fb_info can thus cause a deadlock. fbmem.c sends the FB_EVENT_BLANK without locking lock_fb_info first, so this change introduces similar behaviour. --- drivers/video/console/fbcon.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c index 6b4fb5c..8546441 100644 --- a/drivers/video/console/fbcon.c +++ b/drivers/video/console/fbcon.c @@ -2333,13 +2333,9 @@ static void fbcon_generic_blank(struct vc_data *vc, struct fb_info *info, vc->vc_video_erase_char = oldc; } - - if (!lock_fb_info(info)) - return; event.info = info; event.data = ␣ fb_notifier_call_chain(FB_EVENT_CONBLANK, &event); - unlock_fb_info(info); } static int fbcon_blank(struct vc_data *vc, int blank, int mode_switch) -- 1.8.1.2
How can I get this reviewed/acked please?
The get_maintainer.pl script can help to discover to whom to address patches. For example, peter@thor:~/src/kernels/next$ ./scripts/get_maintainer.pl -f drivers/video/console/fbcon.c Jean-Christophe Plagniol-Villard <plagn...@jcrosoft.com> (maintainer:FRAMEBUFFER LAYER) Tomi Valkeinen <tomi.valkei...@ti.com> (maintainer:FRAMEBUFFER LAYER) Dave Airlie <airl...@redhat.com> (commit_signer:5/11=45%) Greg Kroah-Hartman <gre...@linuxfoundation.org> (commit_signer:4/11=36%) Wang YanQing <udkni...@gmail.com> (commit_signer:4/11=36%) Andrew Morton <a...@linux-foundation.org> (commit_signer:3/11=27%) Kamal Mostafa <ka...@whence.com> (commit_signer:1/11=9%) linux-fb...@vger.kernel.org (open list:FRAMEBUFFER LAYER) linux-kernel@vger.kernel.org (open list) In this case, you'll want to send this patch addressed to the two maintainers and cc linux-fbdev and linux-kernel. You can cc me if you want. This is covered in Documentation/SubmittingPatches, which also covers the required subject line format <hint: too long, needs subsystem identifier>. Also, if you have the lockdep report of the deadlock, it's customary to include it in the commit message. Regards, Peter Hurley PS - Don't put stuff after the '--' tag at the end of the patch. Many mailers treat that as don't care. I missed your question first time around because Thunderbird grays that text :( -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
