diff --git a/fbcon-fix-race-condition-between-console-lock-and-cursor-timer.patch b/fbcon-fix-race-condition-between-console-lock-and-cursor-timer.patch new file mode 100644 index 000000000..992bd252f --- /dev/null +++ b/fbcon-fix-race-condition-between-console-lock-and-cursor-timer.patch @@ -0,0 +1,89 @@ + +Delivered-To: jwboyer@gmail.com +Received: by 10.229.184.7 with SMTP id ci7csp32184qcb; + Mon, 20 Aug 2012 23:40:20 -0700 (PDT) +Received: by 10.236.195.97 with SMTP id o61mr24210886yhn.17.1345531220620; + Mon, 20 Aug 2012 23:40:20 -0700 (PDT) +Return-Path: +Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) + by mx.google.com with ESMTP id c5si239413anp.5.2012.08.20.23.40.20; + Mon, 20 Aug 2012 23:40:20 -0700 (PDT) +Received-SPF: pass (google.com: domain of airlied@redhat.com designates 209.132.183.28 as permitted sender) client-ip=209.132.183.28; +Authentication-Results: mx.google.com; spf=pass (google.com: domain of airlied@redhat.com designates 209.132.183.28 as permitted sender) smtp.mail=airlied@redhat.com +Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) + by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q7L6eJ4K014799 + (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); + Tue, 21 Aug 2012 02:40:19 -0400 +Received: from prime.bne.redhat.com (dhcp-41-76.bne.redhat.com [10.64.41.76]) + by int-mx01.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id q7L6eFfB029177; + Tue, 21 Aug 2012 02:40:16 -0400 +From: Dave Airlie +To: linux-fbdev@vger.kernel.org +Cc: dri-devel@lists.sf.net, linux-kernel@vger.kernel.org, + Linus , + Alan Cox , + Randy Dunlap , Josh Boyer , + Dave Airlie +Subject: [PATCH] fbcon: fix race condition between console lock and cursor timer +Date: Tue, 21 Aug 2012 16:40:07 +1000 +Message-Id: <1345531207-24926-1-git-send-email-airlied@redhat.com> +X-Scanned-By: MIMEDefang 2.67 on 10.5.11.11 + +So we've had a fair few reports of fbcon handover breakage between +efi/vesafb and i915 surface recently, so I dedicated a couple of +days to finding the problem. + +Essentially the last thing we saw was the conflicting framebuffer +message and that was all. + +So after much tracing with direct netconsole writes (printks +under console_lock not so useful), I think I found the race. + +Thread A (driver load) Thread B (timer thread) + unbind_con_driver -> | + bind_con_driver -> | + vc->vc_sw->con_deinit -> | + fbcon_deinit -> | + console_lock() | + | | + | fbcon_flashcursor timer fires + | console_lock() <- blocked for A + | + | +fbcon_del_cursor_timer -> + del_timer_sync + (BOOM) + +Of course because all of this is under the console lock, +we never see anything, also since we also just unbound the active +console guess what we never see anything. + +Hopefully this fixes the problem for anyone seeing vesafb->kms +driver handoff. + +Signed-off-by: David Airlie +--- + drivers/video/console/fbcon.c | 6 +++++- + 1 file changed, 5 insertions(+), 1 deletion(-) + +diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c +index 2e471c2..f8a79fc 100644 +--- a/drivers/video/console/fbcon.c ++++ b/drivers/video/console/fbcon.c +@@ -372,8 +372,12 @@ static void fb_flashcursor(struct work_struct *work) + struct vc_data *vc = NULL; + int c; + int mode; ++ int ret; ++ ++ ret = console_trylock(); ++ if (ret == 0) ++ return; + +- console_lock(); + if (ops && ops->currcon != -1) + vc = vc_cons[ops->currcon].d; + +-- +1.7.10.2 + diff --git a/kernel.spec b/kernel.spec index 05f65d2c0..39edbfe80 100644 --- a/kernel.spec +++ b/kernel.spec @@ -62,7 +62,7 @@ Summary: The Linux kernel # For non-released -rc kernels, this will be appended after the rcX and # gitX tags, so a 3 here would become part of release "0.rcX.gitX.3" # -%global baserelease 1 +%global baserelease 2 %global fedora_build %{baserelease} # base_sublevel is the kernel version we're starting with and patching @@ -747,6 +747,8 @@ Patch22001: selinux-apply-different-permission-to-ptrace-child.patch #rhbz 836742 Patch22059: uvcvideo-Reset-bytesused-field-when-recycling-erroneous-buffer.patch +Patch22065: fbcon-fix-race-condition-between-console-lock-and-cursor-timer.patch + # END OF PATCH DEFINITIONS %endif @@ -1437,6 +1439,8 @@ ApplyPatch selinux-apply-different-permission-to-ptrace-child.patch #rhbz 836742 ApplyPatch uvcvideo-Reset-bytesused-field-when-recycling-erroneous-buffer.patch +ApplyPatch fbcon-fix-race-condition-between-console-lock-and-cursor-timer.patch + # END OF PATCH APPLICATIONS %endif @@ -2299,6 +2303,9 @@ fi # ||----w | # || || %changelog +* Tue Aug 21 2012 Josh Boyer +- Add patch from Dave Airlie to fix fb cursor vs grub2 gfxterm hang + * Mon Aug 20 2012 Josh Boyer - 3.6.0-0.rc2.git1.1 - Linux v3.6-rc2-206-g10c63c9