This is a note to let you know that I've just added the patch titled
serial/imx: read cts state only after acking cts change irq
to the 2.6.32-longterm tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/longterm/longterm-queue-2.6.32.git;a=summary
The filename of the patch is:
serial-imx-read-cts-state-only-after-acking-cts-change-irq.patch
and it can be found in the queue-2.6.32 subdirectory.
If you, or anyone else, feels it should not be added to the 2.6.32 longterm
tree,
please let <[email protected]> know about it.
From 5680e94148a86e8c31fdc5cb0ea0d5c6810c05b0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= <[email protected]>
Date: Mon, 11 Apr 2011 10:59:09 +0200
Subject: serial/imx: read cts state only after acking cts change irq
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From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= <[email protected]>
commit 5680e94148a86e8c31fdc5cb0ea0d5c6810c05b0 upstream.
If cts changes between reading the level at the cts input (USR1_RTSS)
and acking the irq (USR1_RTSD) the last edge doesn't generate an irq and
uart_handle_cts_change is called with a outdated value for cts.
The race was introduced by commit
ceca629 ([ARM] 2971/1: i.MX uart handle rts irq)
Reported-by: Arwed Springer <[email protected]>
Tested-by: Arwed Springer <[email protected]>
Signed-off-by: Uwe Kleine-König <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/serial/imx.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/serial/imx.c
+++ b/drivers/serial/imx.c
@@ -382,12 +382,13 @@ static void imx_start_tx(struct uart_por
static irqreturn_t imx_rtsint(int irq, void *dev_id)
{
struct imx_port *sport = dev_id;
- unsigned int val = readl(sport->port.membase + USR1) & USR1_RTSS;
+ unsigned int val;
unsigned long flags;
spin_lock_irqsave(&sport->port.lock, flags);
writel(USR1_RTSD, sport->port.membase + USR1);
+ val = readl(sport->port.membase + USR1) & USR1_RTSS;
uart_handle_cts_change(&sport->port, !!val);
wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
Patches currently in longterm-queue-2.6.32 which might be from
[email protected] are
/home/gregkh/linux/longterm/longterm-queue-2.6.32/queue-2.6.32/serial-imx-read-cts-state-only-after-acking-cts-change-irq.patch
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