Re: [Linux-fbdev-devel] [fbdev] Lockdep error

[Dmitry <dbaryshkov@gmail.com>]

2008/9/17 Krzysztof Helt <krzysztof.h1@wp.pl>:
> On Mon, 15 Sep 2008 16:21:52 +0400
> Dmitry Baryshkov <dbaryshkov@gmail.com> wrote:
>
>> Hi,
>>
>> After doing
>> # echo 1 > /sys/class/graphics/fb0/blank
>> I got the following in my kernel log:
>>
>> =============================================
>> [ INFO: possible recursive locking detected ]
>> 2.6.27-rc6-00086-gda63874-dirty #97
>> ---------------------------------------------
>> echo/1564 is trying to acquire lock:
>>  ((fb_notifier_list).rwsem){..--}, at: [<c005a384>] __blocking_notifier_call_chain+0x38/0x6c
>>
>
> Does the patch below fix the problem for you?

Sorry for the delay.
Yes, the patch does fix the issue for me. Thank you.

>
> Kind regards,
> Krzysztof
>
> diff -urp linux-ref/drivers/video/console/fbcon.c linux-mm/drivers/video/console/fbcon.c
> --- linux-ref/drivers/video/console/fbcon.c     2008-09-05 23:38:47.000000000 +0200
> +++ linux-mm/drivers/video/console/fbcon.c      2008-09-16 23:30:52.309604454 +0200
> @@ -2400,11 +2400,15 @@ static int fbcon_blank(struct vc_data *v
>
>        if (!fbcon_is_inactive(vc, info)) {
>                if (ops->blank_state != blank) {
> +                       int ret = 1;
> +
>                        ops->blank_state = blank;
>                        fbcon_cursor(vc, blank ? CM_ERASE : CM_DRAW);
>                        ops->cursor_flash = (!blank);
>
> -                       if (fb_blank(info, blank))
> +                       if (info->fbops->fb_blank)
> +                               ret = info->fbops->fb_blank(blank, info);
> +                       if (ret)
>                                fbcon_generic_blank(vc, info, blank);
>                }
>
>



-- 
With best wishes
Dmitry