Re: [PATCH v3] fbcon: Do not takeover the console from atomic context

From
Hans de Goede <hidden>
Date
2018-08-11 10:28:46
Also in
dri-devel
Reply to
Bartlomiej Zolnierkiewicz, 2018-08-10
Hi,

On 10-08-18 17:22, Bartlomiej Zolnierkiewicz wrote:
On Friday, August 10, 2018 01:27:57 PM Hans de Goede wrote:
quoted
Taking over the console involves allocating mem with GFP_KERNEL, talking
to drm drivers, etc. So this should not be done from an atomic context.

But the console-output trigger deferred console takeover may happen from an
atomic context, which leads to "BUG: sleeping function called from invalid
context" errors.

This commit fixes these errors by doing the deferred takeover from a
workqueue.

Signed-off-by: Hans de Goede <redacted>
Patch queued for 4.19, thanks.
quoted
@@ -3607,8 +3620,8 @@ static int fbcon_output_notifier(struct notifier_block *nb,
  	deferred_takeover = false;
  	logo_shown = FBCON_LOGO_DONTSHOW;
  
-	for_each_registered_fb(i)
-		fbcon_fb_registered(registered_fb[i]);
+	/* We may get called in atomic context */
+	schedule_work(&fbcon_deferred_takeover_work);
After above change gcc now complains about unused variable:

drivers/video/fbdev/core/fbcon.c: In function ‘fbcon_output_notifier’:
drivers/video/fbdev/core/fbcon.c:3613:6: warning: unused variable ‘i’ [-Wunused-variable]
   int i;
       ^

I fixed this while applying the patch.
Ah yes, thank you for fixing this,

Regards,

Hans
Thread (3 messages) 3 messages, 2 authors, 2018-08-11
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