Re: tty, vt: lockdep warnings (Patch v3)

2012-11-13 Thread Sasha Levin
On Fri, Nov 9, 2012 at 2:42 PM, Sasha Levin wrote: > On 11/09/2012 02:34 PM, Hugh Dickins wrote: >> On Thu, 8 Nov 2012, Alan Cox wrote: >>> commit f35b3fbf24c4e4debb6a7a864b09854ccc2a22e7 >>> Author: Alan Cox >>> Date: Wed Nov 7 16:35:08 2012 + >>> >>> fb: Rework locking to fix lock ord

Re: tty, vt: lockdep warnings (Patch v3)

2012-11-09 Thread Sasha Levin
On 11/09/2012 02:34 PM, Hugh Dickins wrote: > On Thu, 8 Nov 2012, Alan Cox wrote: >> commit f35b3fbf24c4e4debb6a7a864b09854ccc2a22e7 >> Author: Alan Cox >> Date: Wed Nov 7 16:35:08 2012 + >> >> fb: Rework locking to fix lock ordering on takeover >> >> Adjust the console layer to

Re: tty, vt: lockdep warnings (Patch v3)

2012-11-09 Thread Hugh Dickins
On Thu, 8 Nov 2012, Alan Cox wrote: > commit f35b3fbf24c4e4debb6a7a864b09854ccc2a22e7 > Author: Alan Cox > Date: Wed Nov 7 16:35:08 2012 + > > fb: Rework locking to fix lock ordering on takeover > > Adjust the console layer to allow a take over call where the caller > already

Re: tty, vt: lockdep warnings (Patch v3)

2012-11-08 Thread Alan Cox
commit f35b3fbf24c4e4debb6a7a864b09854ccc2a22e7 Author: Alan Cox Date: Wed Nov 7 16:35:08 2012 + fb: Rework locking to fix lock ordering on takeover Adjust the console layer to allow a take over call where the caller already holds the locks. Make the fb layer lock in order.

Re: tty, vt: lockdep warnings

2012-11-07 Thread Alan Cox
On Wed, 07 Nov 2012 17:15:45 +0100 Bjørn Mork wrote: > Alan Cox writes: > > > + > > +static int bind_con_driver(const struct consw *csw, int first, int last, > > + int deflt) > > +{ > > + int ret; > > + > > + console_unlock(); > > console_lock() maybe... Thanks I'l

Re: tty, vt: lockdep warnings

2012-11-07 Thread Bjørn Mork
Alan Cox writes: > + > +static int bind_con_driver(const struct consw *csw, int first, int last, > +int deflt) > +{ > + int ret; > + > + console_unlock(); console_lock() maybe... > + ret = do_bind_con_driver(csw, first, last, deflt); > + console_unlo

Re: tty, vt: lockdep warnings

2012-11-07 Thread Alan Cox
On Wed, 07 Nov 2012 08:47:08 -0500 Sasha Levin wrote: > On 11/06/2012 12:38 PM, Alan Cox wrote: > >> > The root > >> > cause is loading two different framebuffers with one taking over from > >> > another - that should be an obscure corner case and once the fuzz > >> testing > >> > can avoid.

Re: tty, vt: lockdep warnings

2012-11-07 Thread Sasha Levin
On 11/06/2012 12:38 PM, Alan Cox wrote: >> > The root >> > cause is loading two different framebuffers with one taking over from >> > another - that should be an obscure corner case and once the fuzz testing >> > can avoid. >> > >> > I had a semi-informed poke at this and came up with a poss

Re: tty, vt: lockdep warnings

2012-11-06 Thread Hugh Dickins
On Tue, 6 Nov 2012, Hugh Dickins wrote: > > Ah, now I actually scan through it, I see references to blank screen: > I'll try taking off your patch and seeing if it came up at screen > blanking time, then put on your patch back on and try again. > I'll report back in an hour or two. Yes, that was

Re: tty, vt: lockdep warnings

2012-11-06 Thread Hugh Dickins
On Tue, 6 Nov 2012, Alan Cox wrote: > On Mon, 5 Nov 2012 12:34:44 -0800 (PST) > Hugh Dickins wrote: > > On Mon, 5 Nov 2012, Alan Cox wrote: > > > > The fbdev potential for deadlock may be years old, but the warning > > > > (and consequent disabling of lockdep from that point on - making it > > > >

Re: tty, vt: lockdep warnings

2012-11-06 Thread Alan Cox
> > The root > > cause is loading two different framebuffers with one taking over from > > another - that should be an obscure corner case and once the fuzz testing > > can avoid. > > > > I had a semi-informed poke at this and came up with a possible patch (not > very tested) > > If this f

Re: tty, vt: lockdep warnings

2012-11-06 Thread Dave Jones
On Tue, Nov 06, 2012 at 04:11:00PM +, Alan Cox wrote: > > But a deadlock we have lived with for years. Without reverting, > > we're prevented from discovering all the new deadlocks we're adding. > > We lived with it locking boxes up on users but not knowing why. Circa 3.5 we got a lot m

Re: tty, vt: lockdep warnings

2012-11-06 Thread Alan Cox
On Mon, 5 Nov 2012 12:34:44 -0800 (PST) Hugh Dickins wrote: > On Mon, 5 Nov 2012, Alan Cox wrote: > > > The fbdev potential for deadlock may be years old, but the warning > > > (and consequent disabling of lockdep from that point on - making it > > > useless to everybody else in need of it) is ne

Re: tty, vt: lockdep warnings

2012-11-05 Thread Hugh Dickins
On Mon, 5 Nov 2012, Alan Cox wrote: > > The fbdev potential for deadlock may be years old, but the warning > > (and consequent disabling of lockdep from that point on - making it > > useless to everybody else in need of it) is new, and comes from the > > commit below in linux-next. > > > > I rever

Re: tty, vt: lockdep warnings

2012-11-05 Thread Alan Cox
> The fbdev potential for deadlock may be years old, but the warning > (and consequent disabling of lockdep from that point on - making it > useless to everybody else in need of it) is new, and comes from the > commit below in linux-next. > > I revert it in my own testing: if there is no quick fix

Re: tty, vt: lockdep warnings

2012-11-05 Thread Hugh Dickins
On Mon, 5 Nov 2012, Sasha Levin wrote: > On 11/05/2012 12:59 PM, Alan Cox wrote: > > On Mon, 5 Nov 2012 12:26:43 -0500 > > Sasha Levin wrote: > > > >> Ping? Should I bisect it? > >> > >> On Fri, Oct 26, 2012 at 9:37 AM, Alan Cox wrote: > >>> On Thu, 25 Oct 2012 15:37:43 -0400 > >>> Sasha Levin

Re: tty, vt: lockdep warnings

2012-11-05 Thread Sasha Levin
On 11/05/2012 12:59 PM, Alan Cox wrote: > On Mon, 5 Nov 2012 12:26:43 -0500 > Sasha Levin wrote: > >> Ping? Should I bisect it? >> >> On Fri, Oct 26, 2012 at 9:37 AM, Alan Cox wrote: >>> On Thu, 25 Oct 2012 15:37:43 -0400 >>> Sasha Levin wrote: >>> Hi all, While fuzzing with trin

Re: tty, vt: lockdep warnings

2012-11-05 Thread Alan Cox
On Mon, 5 Nov 2012 12:26:43 -0500 Sasha Levin wrote: > Ping? Should I bisect it? > > On Fri, Oct 26, 2012 at 9:37 AM, Alan Cox wrote: > > On Thu, 25 Oct 2012 15:37:43 -0400 > > Sasha Levin wrote: > > > >> Hi all, > >> > >> While fuzzing with trinity inside a KVM tools (lkvm) guest running late

Re: tty, vt: lockdep warnings

2012-11-05 Thread Sasha Levin
Ping? Should I bisect it? On Fri, Oct 26, 2012 at 9:37 AM, Alan Cox wrote: > On Thu, 25 Oct 2012 15:37:43 -0400 > Sasha Levin wrote: > >> Hi all, >> >> While fuzzing with trinity inside a KVM tools (lkvm) guest running latest >> -next kernel, >> I've stumbled on the following spew: > > Looks re

Re: tty, vt: lockdep warnings

2012-10-26 Thread Alan Cox
On Thu, 25 Oct 2012 15:37:43 -0400 Sasha Levin wrote: > Hi all, > > While fuzzing with trinity inside a KVM tools (lkvm) guest running latest > -next kernel, > I've stumbled on the following spew: Looks real enough but its not a tty/vt layer spew. This is all coming out of the core framebuffer