From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934941AbcKNC1u (ORCPT ); Sun, 13 Nov 2016 21:27:50 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:47126 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935305AbcKNCZy (ORCPT ); Sun, 13 Nov 2016 21:25:54 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Peter Rosin" , "Wolfram Sang" Date: Mon, 14 Nov 2016 00:14:20 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 314/346] i2c: mux: pca954x: retry updating the mux selection on failure In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.39-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Peter Rosin commit 463e8f845cbf1c01e4cc8aeef1703212991d8e1e upstream. 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 Signed-off-by: Wolfram Sang [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- drivers/i2c/muxes/i2c-mux-pca954x.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/i2c/muxes/i2c-mux-pca954x.c +++ b/drivers/i2c/muxes/i2c-mux-pca954x.c @@ -161,7 +161,7 @@ static int pca954x_select_chan(struct i2 /* Only select the channel if its different from the last channel */ if (data->last_chan != regval) { ret = pca954x_reg_write(adap, client, regval); - data->last_chan = regval; + data->last_chan = ret ? 0 : regval; } return ret;