Re: [PATCH v3 17/23] counter: intel-qep: Convert to new counter registration

From: Jarkko Nikula <jarkko.nikula@linux.intel.com>
To: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
	"William Breathitt Gray" <vilhelm.gray@gmail.com>
Cc: linux-iio@vger.kernel.org, kernel@pengutronix.de,
	Jonathan Cameron <Jonathan.Cameron@huawei.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 17/23] counter: intel-qep: Convert to new counter registration
Date: Thu, 30 Dec 2021 12:26:41 +0200	[thread overview]
Message-ID: <87af88b5-048d-8671-53b7-30dfcba3f19f@linux.intel.com> (raw)
In-Reply-To: <20211229154441.38045-18-u.kleine-koenig@pengutronix.de>

On 12/29/21 17:44, Uwe Kleine-König wrote:
> This fixes device lifetime issues where it was possible to free a live
> struct device.
> 
> Fixes: b711f687a1c1 ("counter: Add support for Intel Quadrature Encoder Peripheral")
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---
>   drivers/counter/intel-qep.c | 28 ++++++++++++++++------------
>   1 file changed, 16 insertions(+), 12 deletions(-)
> 
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>

Following test will cause an oops usually after a few iterations before 
this patch:

while :; do { sleep 5; echo bang; } > /dev/counter0 & sleep 1; echo 
0000:00:18.4 >/sys/bus/pci/drivers/intel-qep/unbind; sleep 8; echo 
0000:00:18.4 >/sys/bus/pci/drivers/intel-qep/bind; done