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From: Nicolas Ferre <nicolas.ferre@atmel.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	<linux-arm-kernel@lists.infradead.org>,
	Alexandre Belloni <alexandre.belloni@free-electrons.com>,
	<linux-serial@vger.kernel.org>
Cc: <linux-kernel@vger.kernel.org>,
	Boris BREZILLON <boris.brezillon@free-electrons.com>,
	Ludovic Desroches <ludovic.desroches@atmel.com>,
	Nicolas Ferre <nicolas.ferre@atmel.com>
Subject: [PATCH 0/4] tty/serial: atmel: rework tasklets and shutdown sequence
Date: Fri, 17 Jun 2016 12:05:45 +0200	[thread overview]
Message-ID: <cover.1466157015.git.nicolas.ferre@atmel.com> (raw)

We experienced some issues with how the atmel_serial driver was dealing with
tasklets.
First, a single tasklet was used for both RX and TX paths which was leading to
calling DMA residue checking routines frequently without reason. So I split the
RX and TX paths with one tasklet for each.
Secondly, as we experienced some deadlocks, I reinforced the shutdown function
of this driver by following the recommended sequence that is described
here:
https://lwn.net/Articles/588457/

The first 3 patches have already been posted on May 12th. The 4th patch is
built on top of them, this is why make a series with them...

Bye,


Ludovic Desroches (1):
  tty/serial: atmel: add comment for the ring buffer size macro

Nicolas Ferre (3):
  tty/serial: atmel: re-integrate status check in irq handler
  tty/serial: atmel: split tx and rx paths
  tty/serial: atmel: enforce tasklet init and termination sequences

 drivers/tty/serial/atmel_serial.c | 129 +++++++++++++++++++++++---------------
 1 file changed, 78 insertions(+), 51 deletions(-)

-- 
2.9.0

             reply	other threads:[~2016-06-17 10:05 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-17 10:05 Nicolas Ferre [this message]
2016-06-17 10:05 ` [RESEND PATCH 1/4] tty/serial: atmel: re-integrate status check in irq handler Nicolas Ferre
2016-06-17 10:05 ` [RESEND PATCH 2/4] tty/serial: atmel: split tx and rx paths Nicolas Ferre
2016-06-17 10:05 ` [RESEND PATCH 3/4] tty/serial: atmel: add comment for the ring buffer size macro Nicolas Ferre
2016-06-17 10:05 ` [PATCH 4/4] tty/serial: atmel: enforce tasklet init and termination sequences Nicolas Ferre
2016-06-25 20:39   ` Greg Kroah-Hartman
2016-06-26  7:44     ` [PATCH v2] " Nicolas Ferre

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