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From: "andy@kernel.org" <andy@kernel.org>
To: YE Chengfeng <cyeaa@connect.ust.hk>
Cc: Linus Walleij <linus.walleij@linaro.org>,
	Bartosz Golaszewski <brgl@bgdev.pl>,
	"linux-gpio@vger.kernel.org" <linux-gpio@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 1/2] gpiolib: cdev: Fix &lr->wait.lock deadlock issue
Date: Mon, 26 Jun 2023 14:01:47 +0300	[thread overview]
Message-ID: <ZJlwG4zzmm4ArMNX@smile.fi.intel.com> (raw)
In-Reply-To: <TYCP286MB1188A94580A60F47CAF892C88A26A@TYCP286MB1188.JPNP286.PROD.OUTLOOK.COM>

On Mon, Jun 26, 2023 at 10:39:56AM +0000, YE Chengfeng wrote:
> linereq_put_event is called from both interrupt context (e.g.,
> edge_irq_thread) and process context (process_hw_ts_thread).
> Therefore, interrupt should be disabled before acquiring lock
> &lr->wait.lock inside linereq_put_event to avoid deadlock when
> the lock is held in process context and edge_irq_thread comes.
> 
> Similarly, linereq_read_unlocked running in process context
> also acquies the same lock. It also need to disable interrupt
> otherwise deadlock could happen if the irq edge_irq_thread
> comes to execution while the lock is held.
> 
> Fix the two potential deadlock issues by spin_lock_bh() and
> spin_lock_irq() separately.

Side note: You have two patches in something that seems to be the series,
but lacks the references in email headers. Whenever you send a series,
do not forget to add --thread to `git send-email`.

-- 
With Best Regards,
Andy Shevchenko



  reply	other threads:[~2023-06-26 11:02 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-06-26 10:39 [PATCH v2 1/2] gpiolib: cdev: Fix &lr->wait.lock deadlock issue YE Chengfeng
2023-06-26 11:01 ` andy [this message]
2023-06-26 11:03 ` andy
     [not found]   ` <TYCP286MB11884755575685089C1BBDC38A26A@TYCP286MB1188.JPNP286.PROD.OUTLOOK.COM>
2023-06-26 11:14     ` 回复: " andy
2023-06-26 15:03       ` 回复: " YE Chengfeng
  -- strict thread matches above, loose matches on Subject: below --
2023-06-26 14:57 Chengfeng Ye

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