linux-kernel - [PATCH] i2c: i2c-mux-pca954x: retry updating the mux selection on failure

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Date:   Wed, 14 Sep 2016 15:24:12 +0200
From:   Peter Rosin <peda@...ntia.se>
To:     "open list:I2C MUXES" <linux-i2c@...r.kernel.org>
CC:     Peter Rosin <peda@...ntia.se>, Wolfram Sang <wsa@...-dreams.de>,
        open list <linux-kernel@...r.kernel.org>
Subject: [PATCH] i2c: i2c-mux-pca954x: retry updating the mux selection on failure

The cached value of the last selected channel prevents retries on the
next call, even on failure to update the selected channel. Fix that.

Signed-off-by: Peter Rosin <peda@...ntia.se>
---
 drivers/i2c/muxes/i2c-mux-pca954x.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c
index 528e755c468f..3278ebf1cc5c 100644
--- a/drivers/i2c/muxes/i2c-mux-pca954x.c
+++ b/drivers/i2c/muxes/i2c-mux-pca954x.c
@@ -164,7 +164,7 @@ static int pca954x_select_chan(struct i2c_mux_core *muxc, u32 chan)
 	/* Only select the channel if its different from the last channel */
 	if (data->last_chan != regval) {
 		ret = pca954x_reg_write(muxc->parent, client, regval);
-		data->last_chan = regval;
+		data->last_chan = ret ? 0 : regval;
 	}
 
 	return ret;
-- 
2.1.4