From: David Lechner <david@lechnology.com>
To: William Breathitt Gray <vilhelm.gray@gmail.com>,
Jarkko Nikula <jarkko.nikula@linux.intel.com>
Cc: jic23@kernel.org, linux-stm32@st-md-mailman.stormreply.com,
kernel@pengutronix.de, a.fatoum@pengutronix.de,
kamel.bouhara@bootlin.com, gwendal@chromium.org,
alexandre.belloni@bootlin.com, linux-iio@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, syednwaris@gmail.com,
patrick.havelange@essensium.com, fabrice.gasnier@st.com,
mcoquelin.stm32@gmail.com, alexandre.torgue@st.com,
o.rempel@pengutronix.de
Subject: Re: [PATCH v12 15/17] counter: Implement events_queue_size sysfs attribute
Date: Sat, 10 Jul 2021 10:43:22 -0500 [thread overview]
Message-ID: <fbf1ba4c-412b-fe22-0e79-76e968a00fb4@lechnology.com> (raw)
In-Reply-To: <YOl1frCrophjhk7y@shinobu>
On 7/10/21 5:25 AM, William Breathitt Gray wrote:
>> and after that
>>
>> [ 16.564403] ================================================
>> [ 16.570725] WARNING: lock held when returning to user space!
>> [ 16.577044] 5.13.0-next-20210706+ #4 Not tainted
>> [ 16.582198] ------------------------------------------------
>> [ 16.588507] cat/331 is leaving the kernel with locks still held!
>> [ 16.595214] 1 lock held by cat/331:
>> [ 16.599103] #0: ffff888102bb3630
>> (&counter->chrdev_lock){+.+.}-{3:3}, at: counter_chrdev_open+0x21/0x60
>> [counter]
>>
>> Jarkko
> I'm not sure how to resolve this warning. The purpose of this lock is to
> limit chrdev to a single open at a time. To accomplish this I grab this
> lock in counter_chrdev_open() and hold it until counter_chrdev_release()
> is called. Is there a better way to accomplish this?
How about using an atomic flag, e.g test_and_set_bit()?
next prev parent reply other threads:[~2021-07-10 15:43 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-05 8:18 [PATCH v12 00/17] Introduce the Counter character device interface William Breathitt Gray
2021-07-05 8:18 ` [PATCH v12 01/17] counter: 104-quad-8: Return error when invalid mode during ceiling_write William Breathitt Gray
2021-07-05 8:18 ` [PATCH v12 02/17] counter: Return error code on invalid modes William Breathitt Gray
2021-07-09 17:40 ` David Lechner
2021-07-05 8:18 ` [PATCH v12 03/17] counter: Standardize to ERANGE for limit exceeded errors William Breathitt Gray
2021-07-05 8:18 ` [PATCH v12 04/17] counter: Rename counter_signal_value to counter_signal_level William Breathitt Gray
2021-07-05 8:18 ` [PATCH v12 05/17] counter: Rename counter_count_function to counter_function William Breathitt Gray
2021-07-05 8:18 ` [PATCH v12 06/17] counter: Internalize sysfs interface code William Breathitt Gray
2021-07-11 9:49 ` Syed Nayyar Waris
2021-07-11 11:42 ` Jonathan Cameron
2021-07-05 8:18 ` [PATCH v12 07/17] counter: Update counter.h comments to reflect sysfs internalization William Breathitt Gray
2021-07-09 17:49 ` David Lechner
2021-07-10 9:41 ` William Breathitt Gray
2021-07-05 8:18 ` [PATCH v12 08/17] docs: counter: Update " William Breathitt Gray
2021-07-09 17:56 ` David Lechner
2021-07-05 8:18 ` [PATCH v12 09/17] counter: Move counter enums to uapi header William Breathitt Gray
2021-07-05 8:18 ` [PATCH v12 10/17] counter: Add character device interface William Breathitt Gray
2021-07-10 19:37 ` David Lechner
2021-07-11 12:20 ` Jonathan Cameron
2021-07-12 10:28 ` William Breathitt Gray
2021-07-05 8:18 ` [PATCH v12 11/17] docs: counter: Document " William Breathitt Gray
2021-07-10 20:15 ` David Lechner
2021-07-11 10:41 ` William Breathitt Gray
2021-07-05 8:19 ` [PATCH v12 12/17] tools/counter: Create Counter tools William Breathitt Gray
2021-07-10 16:53 ` David Lechner
2021-07-11 11:28 ` William Breathitt Gray
2021-07-11 14:05 ` David Lechner
2021-07-11 13:22 ` Jonathan Cameron
2021-07-05 8:19 ` [PATCH v12 13/17] counter: Implement signalZ_action_component_id sysfs attribute William Breathitt Gray
2021-07-10 16:20 ` David Lechner
2021-07-05 8:19 ` [PATCH v12 14/17] counter: Implement *_component_id sysfs attributes William Breathitt Gray
2021-07-10 17:06 ` David Lechner
2021-07-11 13:28 ` Jonathan Cameron
2021-07-11 14:08 ` David Lechner
2021-07-12 10:19 ` Jonathan Cameron
2021-07-05 8:19 ` [PATCH v12 15/17] counter: Implement events_queue_size sysfs attribute William Breathitt Gray
2021-07-06 7:48 ` Dan Carpenter
2021-07-06 11:40 ` Jarkko Nikula
2021-07-10 10:25 ` William Breathitt Gray
2021-07-10 15:43 ` David Lechner [this message]
2021-07-10 16:08 ` David Lechner
2021-07-10 17:53 ` David Lechner
2021-07-11 9:12 ` William Breathitt Gray
2021-07-05 8:19 ` [PATCH v12 16/17] counter: 104-quad-8: Replace mutex with spinlock William Breathitt Gray
2021-07-05 8:19 ` [PATCH v12 17/17] counter: 104-quad-8: Add IRQ support for the ACCES 104-QUAD-8 William Breathitt Gray
2021-07-11 13:44 ` Jonathan Cameron
2021-07-12 10:59 ` William Breathitt Gray
2021-07-06 11:40 ` [PATCH v12 00/17] Introduce the Counter character device interface Jarkko Nikula
2021-07-07 0:28 ` William Breathitt Gray
2021-07-11 13:48 ` Jonathan Cameron
2021-07-12 10:48 ` William Breathitt Gray
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