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Date: Tue, 2 Apr 2024 20:14:27 +0300
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Hugo Villeneuve <hugo@hugovil.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org,
	Jiri Slaby <jirislaby@kernel.org>
Subject: Re: [PATCH v1 01/16] serial: max3100: Lock port->lock when calling
 uart_handle_cts_change()
Message-ID: <Zgw881ApbwJrozAw@smile.fi.intel.com>
References: <20240402154219.3583679-1-andriy.shevchenko@linux.intel.com>
 <20240402154219.3583679-2-andriy.shevchenko@linux.intel.com>
 <20240402130715.7f1292b774ee0b2f056a6e95@hugovil.com>
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Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo

On Tue, Apr 02, 2024 at 01:07:15PM -0400, Hugo Villeneuve wrote:
> On Tue,  2 Apr 2024 18:38:07 +0300
> Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:
> 
> Hi Andy,
> 
> > uart_handle_cts_change() has to be called with port lock taken,
> > Since we run it in a separate work, the lcok maybe not taken at
> 
> lcok -> lock
> 
> and possibly: "may not be taken" ?

Thanks, I'll fix this in case a new version is required.

> > the time of running. Make sure that it's taken by explicitly doing
> > that. Without it we got a splat:
> > 
> >   WARNING: CPU: 0 PID: 10 at drivers/tty/serial/serial_core.c:3491 uart_handle_cts_change+0xa6/0xb0
> >   ...
> >   Workqueue: max3100-0 max3100_work [max3100]
> >   RIP: 0010:uart_handle_cts_change+0xa6/0xb0
> >   ...
> >    max3100_handlerx+0xc5/0x110 [max3100]
> >    max3100_work+0x12a/0x340 [max3100]

-- 
With Best Regards,
Andy Shevchenko