Thread (3 messages) 3 messages, 3 authors, 2013-01-25

Re: [PATCH] fbcon: fix locking harder

From: Daniel Vetter <hidden>
Date: 2013-01-25 15:55:43
Also in: lkml

On Fri, Jan 25, 2013 at 2:43 AM, Dave Airlie [off-list ref] wrote:
Okay so Alan's patch handled the case where there was no registered fbcon,
however the other path entered in set_con2fb_map pit.

In there we called fbcon_takeover, but we also took the console lock in a couple
of places. So push the console lock out to the callers of set_con2fb_map,

this means fbmem and switcheroo needed to take the lock around the fb notifier
entry points that lead to this.

This should fix the efifb regression seen by Maarten.

Signed-off-by: Dave Airlie <airlied@redhat.com>
---
 drivers/gpu/vga/vga_switcheroo.c |  3 +++
 drivers/video/console/fbcon.c    | 11 ++++++++---
 drivers/video/fbmem.c            |  2 ++
 3 files changed, 13 insertions(+), 3 deletions(-)
[cut]
quoted hunk ↗ jump to hunk
        ret = vgasr_priv.handler->switchto(new_client->id);
diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c
index 2aef9ca..2e2d959 100644
--- a/drivers/video/console/fbcon.c
+++ b/drivers/video/console/fbcon.c
@@ -842,6 +842,8 @@ static void con2fb_init_display(struct vc_data *vc, struct fb_info *info,
  *
  *     Maps a virtual console @unit to a frame buffer device
  *     @newidx.
+ *
+ *     This should be called with the console lock held.
  */
 static int set_con2fb_map(int unit, int newidx, int user)
 {
What about throwing a WARN_CONSOLE_UNLOCKED(); in here to make sure
this new rule is obeyed?
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
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