All of lore.kernel.org
 help / color / mirror / Atom feed
From: Marc Zyngier <maz@kernel.org>
To: gregkh@linuxfoundation.org
Cc: khilman@baylibre.com, linux-kernel@vger.kernel.org,
	linux-serial@vger.kernel.org, linux-amlogic@lists.infradead.org,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	kernel-team@android.com
Subject: [PATCH] tty: serial: meson_uart: Init port lock early
Date: Sun,  5 Jul 2020 10:27:36 +0100	[thread overview]
Message-ID: <20200705092736.1030598-1-maz@kernel.org> (raw)

The meson UART driver triggers a lockdep splat at boot time, due
to the new expectation that the driver has to initialize the
per-port spinlock itself.

It remains unclear why a double initialization of the port
spinlock is a desirable outcome, but in the meantime let's
fix the splat.

Fixes: a3cb39d258ef ("serial: core: Allow detach and attach serial device for console")
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/tty/serial/meson_uart.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c
index d2c08b760f83..386e39c90628 100644
--- a/drivers/tty/serial/meson_uart.c
+++ b/drivers/tty/serial/meson_uart.c
@@ -759,6 +759,9 @@ static int meson_uart_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	/* Init the spinlock early in case this is the console */
+	spin_lock_init(&port->lock);
+
 	port->iotype = UPIO_MEM;
 	port->mapbase = res_mem->start;
 	port->mapsize = resource_size(res_mem);
-- 
2.26.2


_______________________________________________
linux-amlogic mailing list
linux-amlogic@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-amlogic

WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org>
To: gregkh@linuxfoundation.org
Cc: khilman@baylibre.com, linux-serial@vger.kernel.org,
	linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org,
	kernel-team@android.com,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Subject: [PATCH] tty: serial: meson_uart: Init port lock early
Date: Sun,  5 Jul 2020 10:27:36 +0100	[thread overview]
Message-ID: <20200705092736.1030598-1-maz@kernel.org> (raw)

The meson UART driver triggers a lockdep splat at boot time, due
to the new expectation that the driver has to initialize the
per-port spinlock itself.

It remains unclear why a double initialization of the port
spinlock is a desirable outcome, but in the meantime let's
fix the splat.

Fixes: a3cb39d258ef ("serial: core: Allow detach and attach serial device for console")
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/tty/serial/meson_uart.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c
index d2c08b760f83..386e39c90628 100644
--- a/drivers/tty/serial/meson_uart.c
+++ b/drivers/tty/serial/meson_uart.c
@@ -759,6 +759,9 @@ static int meson_uart_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	/* Init the spinlock early in case this is the console */
+	spin_lock_init(&port->lock);
+
 	port->iotype = UPIO_MEM;
 	port->mapbase = res_mem->start;
 	port->mapsize = resource_size(res_mem);
-- 
2.26.2


             reply	other threads:[~2020-07-05  9:28 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-05  9:27 Marc Zyngier [this message]
2020-07-05  9:27 ` [PATCH] tty: serial: meson_uart: Init port lock early Marc Zyngier
2020-07-05 10:07 ` Andy Shevchenko
2020-07-05 10:07   ` Andy Shevchenko
2020-07-05 10:28   ` Marc Zyngier
2020-07-05 10:28     ` Marc Zyngier
2020-07-05 11:22     ` Andy Shevchenko
2020-07-05 11:22       ` Andy Shevchenko
2020-07-05 15:51       ` Marc Zyngier
2020-07-05 15:51         ` Marc Zyngier

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200705092736.1030598-1-maz@kernel.org \
    --to=maz@kernel.org \
    --cc=andriy.shevchenko@linux.intel.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=kernel-team@android.com \
    --cc=khilman@baylibre.com \
    --cc=linux-amlogic@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-serial@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.