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[PATCH v2 2/2] i2c: mediatek: Fixup i2c ack error interrupt handling

From Eddie Huang <eddie.huang@mediatek.com>
Newsgroups linux.kernel
Subject [PATCH v2 2/2] i2c: mediatek: Fixup i2c ack error interrupt handling
Date 2015-08-06 09:30 +0200
Message-ID <pUnMJ-1Zx-9@gated-at.bofh.it> (permalink)
References <pUnMJ-1Zx-5@gated-at.bofh.it>
Organization linux.* mail to news gateway

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When occur i2c ack error, i2c controller generate two interrupts,
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@mediatek.com>
Signed-off-by: Eddie Huang <eddie.huang@mediatek.com>
---
 drivers/i2c/busses/i2c-mt65xx.c |   15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index e28ad4c..c02e6c0 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -557,15 +557,22 @@ static irqreturn_t mtk_i2c_irq(int irqno, void *dev_id)
 {
 	struct mtk_i2c *i2c = dev_id;
 	u16 restart_flag = 0;
+	u16 intr_stat;
 
 	if (i2c->dev_comp->auto_restart)
 		restart_flag = I2C_RS_TRANSFER;
 
-	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);
+	intr_stat = readw(i2c->base + OFFSET_INTR_STAT);
+	writew(intr_stat, i2c->base + OFFSET_INTR_STAT);
 
-	complete(&i2c->msg_complete);
+	/*
+	 * when occurs ack error, i2c controller generate two interrupts
+	 * first is the ack error interrupt, then the complete interrupt
+	 * i2c->irq_stat need keep the two interrupt value.
+	 */
+	i2c->irq_stat |= intr_stat;
+	if (i2c->irq_stat & (I2C_TRANSAC_COMP | restart_flag))
+		complete(&i2c->msg_complete);
 
 	return IRQ_HANDLED;
 }
-- 
1.7.9.5

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Thread

[PATCH v2 0/2] Mediatek I2C fixup  Eddie Huang <eddie.huang@mediatek.com> - 2015-08-06 09:30 +0200
  [PATCH v2 2/2] i2c: mediatek: Fixup i2c ack error interrupt handling Eddie Huang <eddie.huang@mediatek.com> - 2015-08-06 09:30 +0200
    Re: [PATCH v2 2/2] i2c: mediatek: Fixup i2c ack error interrupt handling Daniel Kurtz <djkurtz@chromium.org> - 2015-08-11 10:40 +0200
    Re: [PATCH v2 2/2] i2c: mediatek: Fixup i2c ack error interrupt  handling Wolfram Sang <wsa@the-dreams.de> - 2015-08-11 17:00 +0200
      Re: [PATCH v2 2/2] i2c: mediatek: Fixup i2c ack error interrupt handling Daniel Kurtz <djkurtz@chromium.org> - 2015-08-12 03:40 +0200
        Re: [PATCH v2 2/2] i2c: mediatek: Fixup i2c ack error interrupt  handling Wolfram Sang <wsa@the-dreams.de> - 2015-08-12 03:50 +0200
  [PATCH v2 1/2] i2c: mediatek: Reset DMA engine in hardware init function Eddie Huang <eddie.huang@mediatek.com> - 2015-08-06 09:30 +0200
    Re: [PATCH v2 1/2] i2c: mediatek: Reset DMA engine in hardware init function Daniel Kurtz <djkurtz@chromium.org> - 2015-08-11 10:40 +0200
    Re: [PATCH v2 1/2] i2c: mediatek: Reset DMA engine in hardware init  function Wolfram Sang <wsa@the-dreams.de> - 2015-08-11 17:00 +0200

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