From: John Ogness <john.ogness@linutronix.de>
To: Junxiao Chang <junxiao.chang@intel.com>,
bigeasy@linutronix.de, tglx@linutronix.de, rostedt@goodmis.org,
linux-kernel@vger.kernel.org
Cc: hao3.li@intel.com, lili.li@intel.com, jianfeng.gao@intel.com,
linux-rt-users@vger.kernel.org
Subject: Re: [PATCH 2/2] printk: nbcon: check uart port is nbcon or not in nbcon_release
Date: Wed, 24 Jan 2024 11:03:39 +0106 [thread overview]
Message-ID: <87il3j9hpo.fsf@jogness.linutronix.de> (raw)
In-Reply-To: <20240123054033.183114-3-junxiao.chang@intel.com>
On 2024-01-23, Junxiao Chang <junxiao.chang@intel.com> wrote:
> Try to release nbcon only if current uart port is nbcon, as it does
> in nbcon_acquire.
The release needs to undo what acquire did. Why should it have its own
checks that would cause it to _not_ undo what acquire did?
Keep in mind that an nbcon console could be unregistered while another
CPU is holding the nbcon lock. The port lock (and nbcon lock) are
protecting access to the hardware. They are not related to console
registration/unregistration.
John
next prev parent reply other threads:[~2024-01-24 9:57 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-17 6:52 [PATCH] printk: nbcon: check uart port is nbcon or not in nbcon_release Junxiao Chang
2024-01-17 8:23 ` John Ogness
2024-01-17 8:45 ` Chang, Junxiao
2024-01-17 10:03 ` John Ogness
2024-01-17 10:24 ` Sebastian Andrzej Siewior
2024-01-17 13:08 ` Chang, Junxiao
2024-01-17 13:42 ` John Ogness
2024-01-23 3:05 ` Chang, Junxiao
2024-01-23 5:40 ` [PATCH 0/2] nbcon locking issue with v6.6.10-rt18 kernel Junxiao Chang
2024-01-23 5:40 ` [PATCH 1/2] printk: nbcon: move locked_port flag to struct uart_port Junxiao Chang
2024-01-24 9:47 ` John Ogness
2024-01-24 10:05 ` Sebastian Andrzej Siewior
2024-01-25 1:08 ` Chang, Junxiao
2024-01-25 13:35 ` Sebastian Andrzej Siewior
2024-01-25 23:20 ` Chang, Junxiao
2024-01-26 7:58 ` John Ogness
2024-01-26 16:39 ` Sebastian Andrzej Siewior
2024-01-23 5:40 ` [PATCH 2/2] printk: nbcon: check uart port is nbcon or not in nbcon_release Junxiao Chang
2024-01-24 9:57 ` John Ogness [this message]
2024-01-26 2:33 ` Chang, Junxiao
2024-01-24 9:40 ` [PATCH 0/2] nbcon locking issue with v6.6.10-rt18 kernel John Ogness
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