From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933025Ab2IFSc2 (ORCPT ); Thu, 6 Sep 2012 14:32:28 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:61693 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932373Ab2IFSc0 (ORCPT ); Thu, 6 Sep 2012 14:32:26 -0400 From: Olof Johansson To: Anton Vorontsov Cc: Rhyland Klein , David Woodhouse , linux-kernel@vger.kernel.org, Olof Johansson Subject: [PATCH] sbs-battery: probe should try talking to the device Date: Thu, 6 Sep 2012 11:32:29 -0700 Message-Id: <1346956349-21980-1-git-send-email-olof@lixom.net> X-Mailer: git-send-email 1.7.10.1.488.g05fbf7a Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Turns out this driver doesn't actually try talking to the device at probe time, so if it's incorrectly configured in the device tree or platform data (or if the battery has been removed from the system), then probe will succeed and every access will sit there and time out. The end result is a possibly laggy system that thinks it has a battery but can never read status, which isn't very useful. Instead, just read any register (I chose status) at probe, and if that fails, don't register the device. Signed-off-by: Olof Johansson --- drivers/power/sbs-battery.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/power/sbs-battery.c b/drivers/power/sbs-battery.c index a65e8f5..2f24253 100644 --- a/drivers/power/sbs-battery.c +++ b/drivers/power/sbs-battery.c @@ -760,6 +760,16 @@ static int __devinit sbs_probe(struct i2c_client *client, skip_gpio: + /* Before we register, we need to make sure we can actually talk + * to the battery. + */ + rc = sbs_read_word_data(client, sbs_data[REG_STATUS].addr); + if (rc < 0) { + dev_err(&client->dev, "%s: Failed to get device status\n", + __func__); + goto exit_psupply; + } + rc = power_supply_register(&client->dev, &chip->power_supply); if (rc) { dev_err(&client->dev, -- 1.7.10.1.488.g05fbf7a