Re: patch "serial: imx: Initialize lock for non-registered console" added to tty-next

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Tue, Jun 16, 2020 at 10:15:23PM +0530, Naresh Kamboju wrote:
> On Tue, 16 Jun 2020 at 12:48, Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> wrote:
> >
> > On Tue, Jun 16, 2020 at 11:45:18AM +0530, Naresh Kamboju wrote:
> > > On Thu, 28 May 2020 at 12:49, <gregkh@linuxfoundation.org> wrote:
> > > >
> > > >
> > > > This is a note to let you know that I've just added the patch titled
> > > >
> > > >     serial: imx: Initialize lock for non-registered console
> > > >
> > > > to my tty git tree which can be found at
> > > >     git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git
> > > > in the tty-next branch.
> > > >
> > > > The patch will show up in the next release of the linux-next tree
> > > > (usually sometime within the next 24 hours during the week.)
> > > >
> > > > The patch will also be merged in the next major kernel release
> > > > during the merge window.
> > > >
> > > > If you have any questions about this process, please let me know.
> > > >
> > > >
> > > > From 8f065acec7573672dd15916e31d1e9b2e785566c Mon Sep 17 00:00:00 2001
> > > > From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> > > > Date: Mon, 25 May 2020 13:59:52 +0300
> > > > Subject: serial: imx: Initialize lock for non-registered console
> > > >
> > > > The commit a3cb39d258ef
> > > > ("serial: core: Allow detach and attach serial device for console")
> > > > changed a bit logic behind lock initialization since for most of the console
> > > > driver it's supposed to have lock already initialized even if console is not
> > > > enabled. However, it's not the case for Freescale IMX console.
> > > >
> > > > Initialize lock explicitly in the ->probe().
> > > >
> > > > Note, there is still an open question should or shouldn't not this driver
> > > > register console properly.
> > > >
> > > > Fixes: a3cb39d258ef ("serial: core: Allow detach and attach serial device for console")
> > > > Reported-by: Guenter Roeck <linux@roeck-us.net>
> > > > Cc: stable <stable@vger.kernel.org>
> > > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> > > > Link: https://lore.kernel.org/r/20200525105952.13744-1-andriy.shevchenko@linux.intel.com
> > > > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > > > ---
> > > >  drivers/tty/serial/imx.c | 3 +++
> > > >  1 file changed, 3 insertions(+)
> > > >
> > > > diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
> > > > index 986d902fb7fe..6b078e395931 100644
> > > > --- a/drivers/tty/serial/imx.c
> > > > +++ b/drivers/tty/serial/imx.c
> > > > @@ -2404,6 +2404,9 @@ static int imx_uart_probe(struct platform_device *pdev)
> > > >                 }
> > > >         }
> > > >
> > > > +       /* We need to initialize lock even for non-registered console */
> > > > +       spin_lock_init(&sport->port.lock);
> > >
> > > On arm64 Hikey devices running stable-rc 5.7 branch kernel reported following
> > > kernel INFO while booting.
> >
> > Does backporting (applying)
> >
> > 8508f4cba308 ("serial: amba-pl011: Make sure we initialize the port.lock spinlock")
> >
> > fix the issue?
> 
> Cherry-pick is successful in the stable-rc/linux-5.7.y branch
> and the reported problem seems to be fixed.
> However,I will test with 100 loop iteration and will confirm again.
> ---
> $ git cherry-pick  8508f4cba30
> [stable-rc-linux-5.7.y 4133416ed382] serial: amba-pl011: Make sure we
> initialize the port.lock spinlock
>  Author: John Stultz <john.stultz@linaro.org>
>  Date: Tue Apr 28 18:40:50 2020 +0000
>  1 file changed, 1 insertion(+)

I've added this patch to the tree now, thanks.

greg k-h