From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932728AbcECASj (ORCPT ); Mon, 2 May 2016 20:18:39 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:59842 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932858AbcECAQr (ORCPT ); Mon, 2 May 2016 20:16:47 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Bjorn Andersson , Stephen Boyd , John Stultz , Dmitry Torokhov Subject: [PATCH 4.4 057/163] Input: pmic8xxx-pwrkey - fix algorithm for converting trigger delay Date: Mon, 2 May 2016 17:11:25 -0700 Message-Id: <20160503000510.409230686@linuxfoundation.org> X-Mailer: git-send-email 2.8.2 In-Reply-To: <20160503000508.556845508@linuxfoundation.org> References: <20160503000508.556845508@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable 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: Greg Kroah-Hartman --- 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 @@ -353,7 +353,8 @@ 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; } @@ -385,8 +386,8 @@ 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) {