From: Laxman Dewangan <ldewangan@nvidia.com>
Date: Mon, 7 May 2012 06:46:19 +0000 (+0530)
Subject: i2c: tegra: notify transfer-complete after clearing status.
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=c889e91d2cc22123f20f40dde0c0a91856a20eea;p=deliverable%2Flinux.git

i2c: tegra: notify transfer-complete after clearing status.

The notification of the transfer complete by calling complete()
should be done after clearing all interrupt status.
This avoids the race condition of misconfigure the i2c controller
in multi-core environment.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: stable@kernel.org
---

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 18067b3ee8c9..8b2e555a9563 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -401,8 +401,6 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
 			disable_irq_nosync(i2c_dev->irq);
 			i2c_dev->irq_disabled = 1;
 		}
-
-		complete(&i2c_dev->msg_complete);
 		goto err;
 	}
 
@@ -411,7 +409,6 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
 			i2c_dev->msg_err |= I2C_ERR_NO_ACK;
 		if (status & I2C_INT_ARBITRATION_LOST)
 			i2c_dev->msg_err |= I2C_ERR_ARBITRATION_LOST;
-		complete(&i2c_dev->msg_complete);
 		goto err;
 	}
 
@@ -429,14 +426,14 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
 			tegra_i2c_mask_irq(i2c_dev, I2C_INT_TX_FIFO_DATA_REQ);
 	}
 
+	i2c_writel(i2c_dev, status, I2C_INT_STATUS);
+	if (i2c_dev->is_dvc)
+		dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS);
+
 	if (status & I2C_INT_PACKET_XFER_COMPLETE) {
 		BUG_ON(i2c_dev->msg_buf_remaining);
 		complete(&i2c_dev->msg_complete);
 	}
-
-	i2c_writel(i2c_dev, status, I2C_INT_STATUS);
-	if (i2c_dev->is_dvc)
-		dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS);
 	return IRQ_HANDLED;
 err:
 	/* An error occurred, mask all interrupts */
@@ -446,6 +443,8 @@ err:
 	i2c_writel(i2c_dev, status, I2C_INT_STATUS);
 	if (i2c_dev->is_dvc)
 		dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS);
+
+	complete(&i2c_dev->msg_complete);
 	return IRQ_HANDLED;
 }