linux-kernel - [PATCH 2/2] i2c: mediatek: Fixup i2c ack error interrupt handling

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1438688693-60275-3-git-send-email-eddie.huang@mediatek.com>
Date:	Tue, 4 Aug 2015 19:44:53 +0800
From:	Eddie Huang <eddie.huang@...iatek.com>
To:	Wolfram Sang <wsa@...-dreams.de>
CC:	<srv_heupstream@...iatek.com>,
	Matthias Brugger <matthias.bgg@...il.com>,
	Liguo Zhang <liguo.zhang@...iatek.com>,
	Xudong Chen <xudong.chen@...iatek.com>,
	Sascha Hauer <s.hauer@...gutronix.de>,
	<linux-i2c@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
	<linux-arm-kernel@...ts.infradead.org>,
	<linux-mediatek@...ts.infradead.org>,
	Eddie Huang <eddie.huang@...iatek.com>
Subject: [PATCH 2/2] i2c: mediatek: Fixup i2c ack error interrupt handling

When occur i2c ack error, mtk_i2c_irq is called twice,
first is the ack error interrupt, then the complete interrupt.
i2c interrupt handler should keep the two interrupt value, and only
call complete() for the complete interrupt.

Signed-off-by: Liguo Zhang <liguo.zhang@...iatek.com>
Signed-off-by: Eddie Huang <eddie.huang@...iatek.com>
---
 drivers/i2c/busses/i2c-mt65xx.c |   18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 055159d..12ce7f8 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -558,16 +558,20 @@ err_exit:
 static irqreturn_t mtk_i2c_irq(int irqno, void *dev_id)
 {
 	struct mtk_i2c *i2c = dev_id;
-	u16 restart_flag = 0;
+	u16 intr_stat = 0;
 
-	if (i2c->dev_comp->auto_restart)
-		restart_flag = I2C_RS_TRANSFER;
+	intr_stat = readw(i2c->base + OFFSET_INTR_STAT);
+	writew(intr_stat, i2c->base + OFFSET_INTR_STAT);
 
-	i2c->irq_stat = readw(i2c->base + OFFSET_INTR_STAT);
-	writew(restart_flag | I2C_HS_NACKERR | I2C_ACKERR
-		| I2C_TRANSAC_COMP, i2c->base + OFFSET_INTR_STAT);
+	/*
+	 * when occurs i2c ack error, mtk_i2c_irq is called twice,
+	 * first is the ack error interrupt, then the complete interrupt,
+	 * i2c->irq_stat need keep the two interrupt value.
+	 */
+	i2c->irq_stat |= intr_stat;
 
-	complete(&i2c->msg_complete);
+	if (i2c->irq_stat & I2C_TRANSAC_COMP)
+		complete(&i2c->msg_complete);
 
 	return IRQ_HANDLED;
 }
-- 
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/