[linux-yocto] Fwd: [PATCH] serial: pch_uart: no need to disable irq for -rt kernel

[Liang Li]

On 2012-11-22 00:06, Darren Hart <dvhart at linux.intel.com> wrote:
> 
> 
> On 11/21/2012 07:53 AM, Bruce Ashfield wrote:
> > On 12-11-21 10:46 AM, Bruce Ashfield wrote:
> >> Looping this via the linux-yocto mailing list as well, since I plan to
> >> merge this to the 3.4 yocto kernel (with a slightly tweaked header),
> >> which shares the same base and will have the same problem.
> >>
> >> Darren: does this look fine to you ?
> > 
> > Cancel this. I *knew* the patch looked familiar .. I already have
> > this fix .. from Darren :)
> 
> Right, that. ;-)
> 

I did not see the patch on the linux-yocto mailing list .. so I guess
you might just send it to Bruce directly.

Thanks.

	Liang Li

> --
> Darren
> 
> > 
> > Cheers,
> > 
> > Bruce
> > 
> >>
> >> Cheers,
> >>
> >> Bruce
> >>
> >>
> >> -------- Original Message --------
> >> Subject: [PATCH] serial: pch_uart: no need to disable irq for -rt kernel
> >> Date: Wed, 21 Nov 2012 16:23:30 +0800
> >> From: Liang Li <liang.li at windriver.com>
> >>
> >> Fix the following call trace when ttyPCH* is used as serial console:
> >>
> >> BUG: sleeping function called from invalid context at
> >> ../linux/kernel/rtmutex.c:646
> >>
> >> in_atomic(): 0, irqs_disabled(): 1, pid: 12, name: kworker/0:1
> >> Pid: 12, comm: kworker/0:1 Tainted: G W
> >> 3.4.16-rt17-preempt-rt #1
> >> Call Trace:
> >> [<c1057236>] __might_sleep+0xd6/0x100
> >> [<c163892c>] rt_spin_lock+0x1c/0x40
> >> [<c1351c18>] pch_console_write+0x58/0x1c0
> >> [<c102a4cb>] __call_console_drivers+0x7b/0xa0
> >> [<c102a653>] _call_console_drivers+0x73/0x120
> >> [<c163c51d>] ? sub_preempt_count+0x7d/0xb0
> >> [<c102a9c1>] console_unlock+0xf1/0x250
> >> [<c1346179>] console_callback+0x79/0x120
> >> [<c1045177>] process_one_work+0x107/0x410
> >> [<c1346100>] ? poke_blanked_console+0xc0/0xc0
> >> [<c1346100>] ? poke_blanked_console+0xc0/0xc0
> >> [<c10459c5>] worker_thread+0x135/0x2e0
> >> [<c1045890>] ? manage_workers.isra.26+0x200/0x200
> >> [<c1045890>] ? manage_workers.isra.26+0x200/0x200
> >> [<c104a5e3>] kthread+0x73/0x80
> >> [<c104a570>] ? __init_kthread_worker+0x40/0x40
> >> [<c163f9fa>] kernel_thread_helper+0x6/0x10
> >> BUG: sleeping function called from invalid context at ...
> >>
> >> Signed-off-by: Liang Li <liang.li at windriver.com>
> >> ---
> >>   drivers/tty/serial/pch_uart.c | 4 ++--
> >>   1 file changed, 2 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
> >> index 7d47514..604fcc0 100644
> >> --- a/drivers/tty/serial/pch_uart.c
> >> +++ b/drivers/tty/serial/pch_uart.c
> >> @@ -1551,7 +1551,7 @@ pch_console_write(struct console *co, const char
> >> *s, unsigned int count)
> >>
> >>       touch_nmi_watchdog();
> >>
> >> -    local_irq_save(flags);
> >> +    local_irq_save_nort(flags);
> >>       if (priv->port.sysrq) {
> >>           spin_lock(&priv->lock);
> >>           /* serial8250_handle_port() already took the port lock */
> >> @@ -1584,7 +1584,7 @@ pch_console_write(struct console *co, const char
> >> *s, unsigned int count)
> >>           spin_unlock(&priv->port.lock);
> >>       if (priv_locked)
> >>           spin_unlock(&priv->lock);
> >> -    local_irq_restore(flags);
> >> +    local_irq_restore_nort(flags);
> >>   }
> >>
> >>   static int __init pch_console_setup(struct console *co, char *options)
> > 
> 
> -- 
> Darren Hart
> Intel Open Source Technology Center
> Yocto Project - Technical Lead - Linux Kernel