summaryrefslogtreecommitdiffstats
path: root/Makefile
diff options
context:
space:
mode:
authorDave Airlie <airlied@redhat.com>2012-08-21 16:29:47 +1000
committerDave Airlie <airlied@redhat.com>2012-08-22 14:00:35 +1000
commitd8636a2717bb3da2a7ce2154bf08de90bb8c87b0 (patch)
tree6a0d94c29669dcec4ad4bc584d2052c54f903a2f /Makefile
parent27fc4f1c0be917b1e5cef934783f9b09e28e92ea (diff)
downloadop-kernel-dev-d8636a2717bb3da2a7ce2154bf08de90bb8c87b0.zip
op-kernel-dev-d8636a2717bb3da2a7ce2154bf08de90bb8c87b0.tar.gz
fbcon: fix race condition between console lock and cursor timer (v1.1)
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. v1.1: add comment suggestion from Alan. Cc: stable@vger.kernel.org Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'Makefile')
0 files changed, 0 insertions, 0 deletions
OpenPOWER on IntegriCloud