From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161478AbcFMSiF (ORCPT ); Mon, 13 Jun 2016 14:38:05 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:43500 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161390AbcFMShd (ORCPT ); Mon, 13 Jun 2016 14:37:33 -0400 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, "John Stultz" , "Stephen Boyd" , "Bjorn Andersson" , "Dmitry Torokhov" Date: Mon, 13 Jun 2016 19:36:37 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 031/114] Input: pmic8xxx-pwrkey - fix algorithm for converting trigger delay 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 3.16.36-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Stephen Boyd commit eda5ecc0a6b865561997e177c393f0b0136fe3b7 upstream. The trigger delay algorithm that converts from microseconds to the register value looks incorrect. According to most of the PMIC documentation, the equation is delay (Seconds) = (1 / 1024) * 2 ^ (x + 4) except for one case where the documentation looks to have a formatting issue and the equation looks like delay (Seconds) = (1 / 1024) * 2 x + 4 Most likely this driver was written with the improper documentation to begin with. According to the downstream sources the valid delays are from 2 seconds to 1/64 second, and the latter equation just doesn't make sense for that. Let's fix the algorithm and the range check to match the documentation and the downstream sources. Reported-by: Bjorn Andersson Fixes: 92d57a73e410 ("input: Add support for Qualcomm PMIC8XXX power key") Signed-off-by: Stephen Boyd Tested-by: John Stultz Acked-by: Bjorn Andersson Signed-off-by: Dmitry Torokhov Signed-off-by: Ben Hutchings --- drivers/input/misc/pmic8xxx-pwrkey.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/drivers/input/misc/pmic8xxx-pwrkey.c +++ b/drivers/input/misc/pmic8xxx-pwrkey.c @@ -94,7 +94,8 @@ static int pmic8xxx_pwrkey_probe(struct if (of_property_read_u32(pdev->dev.of_node, "debounce", &kpd_delay)) kpd_delay = 15625; - if (kpd_delay > 62500 || kpd_delay == 0) { + /* Valid range of pwr key trigger delay is 1/64 sec to 2 seconds. */ + if (kpd_delay > USEC_PER_SEC * 2 || kpd_delay < USEC_PER_SEC / 64) { dev_err(&pdev->dev, "invalid power key trigger delay\n"); return -EINVAL; } @@ -124,8 +125,8 @@ static int pmic8xxx_pwrkey_probe(struct pwr->name = "pmic8xxx_pwrkey"; pwr->phys = "pmic8xxx_pwrkey/input0"; - delay = (kpd_delay << 10) / USEC_PER_SEC; - delay = 1 + ilog2(delay); + delay = (kpd_delay << 6) / USEC_PER_SEC; + delay = ilog2(delay); err = regmap_read(regmap, PON_CNTL_1, &pon_cntl); if (err < 0) {