From: Wolfram Sang <wsa+renesas@sang-engineering.com>
Date: Thu, 9 Nov 2017 22:20:53 +0000 (+0100)
Subject: i2c: sh_mobile: avoid unnecessary register read
X-Git-Tag: v4.16-rc1~77^2~59
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=2967f9ca8b0dc8d924e0f14c55d1e73d9c6c4975;p=thirdparty%2Fkernel%2Flinux.git

i2c: sh_mobile: avoid unnecessary register read

There is no data when the first WAIT interrupt arrives. No need to read
something then.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
---

diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c
index 80561ffbcf7b4..40a66d466c3c4 100644
--- a/drivers/i2c/busses/i2c-sh_mobile.c
+++ b/drivers/i2c/busses/i2c-sh_mobile.c
@@ -433,8 +433,9 @@ static int sh_mobile_i2c_isr_rx(struct sh_mobile_i2c_data *pd)
 				break;
 			}
 			data = i2c_op(pd, OP_RX_STOP_DATA, 0);
-		} else
+		} else if (real_pos >= 0) {
 			data = i2c_op(pd, OP_RX, 0);
+		}
 
 		if (real_pos >= 0)
 			pd->msg->buf[real_pos] = data;