[PATCH] spi-dw: delete cur_msg when pump message and transfer hasfinished

[Xiao Jin]

From: xiao jin <jin.xiao@xxxxxxxxx>
Date: Tue, 20 Nov 2012 13:45:47 +0800
Subject: [PATCH] spi-dw: delete cur_msg when pump message and transfer
has finished

We see DPM device timeout happened in spi_max3111 when system suspend.

The root cause is related to the time we delete msg from dw_spi queue.

Below is the scenario how timeout happened.
step1, max3110_main_thread pump the dw_spi msg and transfer it. And
the msg is deleted from dw_spi queue right now.
step2, runtime suspend happened, there is no msg in the dw_spi queue,
it's permitted to enter into D0i3.
step3, After resume from D0i3, irq will not come for ever,
max3110_main_thread still wait for the completion of last pump message
transfer.
step4, system suspend, serial_m3110_shutdown call max3110_out and
try to lock the mutex, but it has been hold and cannot be released
by max3110_main_thread for ever.
step5, DPM device timer timeout.

This patch is to delete the cur msg when msg complete.

Signed-off-by: xiao jin <jin.xiao@xxxxxxxxx>
---
 drivers/spi/spi-dw.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
index d1a495f..f6bf693 100644
--- a/drivers/spi/spi-dw.c
+++ b/drivers/spi/spi-dw.c
@@ -268,6 +268,7 @@ static void giveback(struct dw_spi *dws)
 
 	spin_lock_irqsave(&dws->lock, flags);
 	msg = dws->cur_msg;
+	list_del_init(&dws->cur_msg->queue);
 	dws->cur_msg = NULL;
 	dws->cur_transfer = NULL;
 	dws->prev_chip = dws->cur_chip;
@@ -571,7 +572,6 @@ static void pump_messages(struct work_struct *work)
 
 	/* Extract head of queue */
 	dws->cur_msg = list_entry(dws->queue.next, struct spi_message, queue);
-	list_del_init(&dws->cur_msg->queue);
 
 	/* Initial message state*/
 	dws->cur_msg->state = START_STATE;
-- 
1.7.1



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