From 9886066c243656ca64d234281e551e9f3ad8db60 Mon Sep 17 00:00:00 2001
From: Gao Pan <pandy.gao@nxp.com>
Date: Wed, 8 Mar 2017 22:29:22 +0800
Subject: [PATCH] MLK-14393 i2c: imx-lpi2c: directly retrun ISR when detect a
NACK
A NACK flag in ISR means i2c bus error. In such codition,
there is no need to do read/write operation. It's better
to return ISR directly and then stop i2c transfer.
Signed-off-by: Gao Pan <pandy.gao@nxp.com>
(cherry-pick from 839d59e48b6fdbd882776a48a88ce26ff14d8b86)
Signed-off-by: Vipul Kumar <vipul_kumar@mentor.com>
(cherry picked from commit 3d05274613f55f4f6745a7d05a856fbc7cb91e6f)
---
drivers/i2c/busses/i2c-imx-lpi2c.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/i2c/busses/i2c-imx-lpi2c.c b/drivers/i2c/busses/i2c-imx-lpi2c.c
index 9db6ccded5e9e7..bbf44ac9502111 100644
--- a/drivers/i2c/busses/i2c-imx-lpi2c.c
+++ b/drivers/i2c/busses/i2c-imx-lpi2c.c
@@ -507,15 +507,17 @@ static irqreturn_t lpi2c_imx_isr(int irq, void *dev_id)
lpi2c_imx_intctrl(lpi2c_imx, 0);
temp = readl(lpi2c_imx->base + LPI2C_MSR);
+ if (temp & MSR_NDF) {
+ complete(&lpi2c_imx->complete);
+ goto ret;
+ }
+
if (temp & MSR_RDF)
lpi2c_imx_read_rxfifo(lpi2c_imx);
-
- if (temp & MSR_TDF)
+ else if (temp & MSR_TDF)
lpi2c_imx_write_txfifo(lpi2c_imx);
- if (temp & MSR_NDF)
- complete(&lpi2c_imx->complete);
-
+ret:
return IRQ_HANDLED;
}
--
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