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From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: Locking in the clk API
Date: Thu, 27 Jan 2011 08:54:38 +0000	[thread overview]
Message-ID: <20110127085438.GA25239@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <4D40F5CC.6080809@codeaurora.org>

On Wed, Jan 26, 2011 at 08:34:20PM -0800, Saravana Kannan wrote:
> I'm not too familiar with serial/tty, does anyone know if the  
> .set_termios needs to be atmoic? If not, we could just change  
> cpm_uart/cpm_uart_core.c to use mutex instead of spinlock.

The locking is there to protect against the interrupt handler accessing
the port->* stuff (which seems to have been forgotten by the cpm driver).

I don't see any reason why clk_set_rate() needs to be under the spinlock
there - we need the reprogramming of the baud rate within the spinlock
on 8250 because of DLAB bit hiding the data registers.  It's also a good
idea that it _is_ within the spinlock along with uart_update_timeout()
to ensure timeouts and the baud rate are updated together.

  reply	other threads:[~2011-01-27  8:54 UTC|newest]

Thread overview: 86+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-01-11  2:16 Locking in the clk API Jeremy Kerr
2011-01-11  3:15 ` Paul Mundt
2011-01-11  4:11   ` Jeremy Kerr
2011-01-11  4:54     ` Paul Mundt
2011-01-20 16:32       ` Ben Dooks
2011-01-20 18:57         ` Russell King - ARM Linux
2011-01-21  3:43           ` Saravana Kannan
2011-01-21  9:31             ` Russell King - ARM Linux
2011-01-11  9:03     ` Sascha Hauer
2011-01-11  9:28       ` Russell King - ARM Linux
2011-01-11 14:34         ` Pavel Machek
2011-01-20 16:29   ` Ben Dooks
2011-01-20 18:56     ` Russell King - ARM Linux
2011-01-20 21:30       ` Nicolas Pitre
2011-01-21  2:06         ` Dima Zavin
2011-01-21  4:12           ` Saravana Kannan
2011-01-21  9:32             ` Russell King - ARM Linux
2011-01-22  1:53               ` Saravana Kannan
2011-01-22  2:24                 ` Colin Cross
2011-01-22  2:56                   ` Saravana Kannan
2011-01-22  9:15                 ` Russell King - ARM Linux
2011-01-24 19:31                   ` Saravana Kannan
2011-01-21 21:03             ` Dima Zavin
2011-01-21 21:53               ` Nicolas Pitre
2011-01-21 22:02                 ` Russell King - ARM Linux
2011-01-21 22:28                   ` Colin Cross
2011-01-21 23:21                     ` Benjamin Herrenschmidt
2011-01-21 23:50                     ` Nicolas Pitre
2011-01-22  1:35                     ` Saravana Kannan
2011-01-22  2:22                       ` Colin Cross
2011-01-21 22:29                   ` Nicolas Pitre
2011-01-21 23:28                 ` Bryan Huntsman
2011-01-11  9:16 ` Russell King - ARM Linux
2011-01-11  9:44   ` Jeremy Kerr
2011-01-11 10:13     ` Paul Mundt
2011-01-11 10:30       ` Jeremy Kerr
2011-01-11 12:18         ` Paul Mundt
2011-01-11 13:52           ` Uwe Kleine-König
2011-01-11 14:35           ` Jeremy Kerr
2011-01-12  3:25             ` Saravana Kannan
2011-01-12  7:40               ` Uwe Kleine-König
2011-01-12  1:54           ` Saravana Kannan
2011-01-12  2:25             ` Paul Mundt
2011-01-20 16:57               ` Ben Dooks
2011-01-20 16:53           ` Ben Dooks
2011-01-20 16:40       ` Ben Dooks
2011-01-11 10:39     ` Uwe Kleine-König
2011-01-11 10:47       ` Russell King - ARM Linux
2011-01-11 10:56         ` Uwe Kleine-König
2011-01-11 11:15       ` Richard Zhao
2011-01-20 17:02         ` Ben Dooks
2011-01-20 19:08           ` Russell King - ARM Linux
2011-01-21  0:09             ` Jassi Brar
2011-01-21  4:47               ` Jassi Brar
2011-01-21  9:39                 ` Russell King - ARM Linux
2011-01-21 10:11                   ` Jassi Brar
2011-01-22  4:08                 ` Richard Zhao
2011-01-22  5:30                   ` Jassi Brar
2011-01-21  7:16             ` Saravana Kannan
2011-01-21  9:40               ` Russell King - ARM Linux
2011-01-22  1:47                 ` Saravana Kannan
2011-01-27  4:34                 ` Saravana Kannan
2011-01-27  8:54                   ` Russell King - ARM Linux [this message]
2011-01-27 20:30                     ` Saravana Kannan
2011-01-27 20:43                       ` Russell King - ARM Linux
2011-01-27 21:07                         ` Alan Cox
2011-01-27 21:11                           ` Russell King - ARM Linux
2011-01-27 21:15                           ` Russell King - ARM Linux
2011-01-28  3:29                           ` Saravana Kannan
2011-01-28  3:27                         ` Saravana Kannan
2011-01-11 12:11   ` Jassi Brar
2011-01-12  2:56   ` Saravana Kannan
2011-01-12  9:03     ` Russell King - ARM Linux
2011-01-15 14:02       ` Christer Weinigel
2011-01-15 14:53         ` Russell King - ARM Linux
2011-01-15 15:03           ` Uwe Kleine-König
2011-01-15 15:15             ` Russell King - ARM Linux
2011-01-15 16:03               ` Uwe Kleine-König
2011-01-15 16:21                 ` Russell King - ARM Linux
2011-01-15 16:31                   ` Uwe Kleine-König
2011-01-16  6:59               ` Grant Likely
2011-01-15 17:07           ` Christer Weinigel
2011-01-15 17:20             ` Russell King - ARM Linux
2011-01-15 17:44               ` Christer Weinigel
2011-01-15 20:30                 ` Russell King - ARM Linux
2011-01-17  1:19 ` Jeremy Kerr

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