From patchwork Wed Apr 13 07:01:05 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "J, KEERTHY" X-Patchwork-Id: 8818521 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id B66639F36E for ; Wed, 13 Apr 2016 07:04:44 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id DB9A32024F for ; Wed, 13 Apr 2016 07:04:43 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id F160A201EC for ; Wed, 13 Apr 2016 07:04:42 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1aqEoi-0002Zr-6X; Wed, 13 Apr 2016 07:02:24 +0000 Received: from comal.ext.ti.com ([198.47.26.152]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1aqEof-0002Tq-SO for linux-arm-kernel@lists.infradead.org; Wed, 13 Apr 2016 07:02:22 +0000 Received: from dflxv15.itg.ti.com ([128.247.5.124]) by comal.ext.ti.com (8.13.7/8.13.7) with ESMTP id u3D71woA013502; Wed, 13 Apr 2016 02:01:58 -0500 Received: from DFLE72.ent.ti.com (dfle72.ent.ti.com [128.247.5.109]) by dflxv15.itg.ti.com (8.14.3/8.13.8) with ESMTP id u3D71wio014480; Wed, 13 Apr 2016 02:01:58 -0500 Received: from dlep32.itg.ti.com (157.170.170.100) by DFLE72.ent.ti.com (128.247.5.109) with Microsoft SMTP Server id 14.3.224.2; Wed, 13 Apr 2016 02:01:57 -0500 Received: from ula0393675.dhcp.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by dlep32.itg.ti.com (8.14.3/8.13.8) with ESMTP id u3D71s3j031749; Wed, 13 Apr 2016 02:01:55 -0500 From: Keerthy To: Subject: [PATCH] pinctrl: pinctrl-single: Fix pcs_parse_bits_in_pinctrl_entry to use __ffs than ffs Date: Wed, 13 Apr 2016 12:31:05 +0530 Message-ID: <1460530865-29085-1-git-send-email-j-keerthy@ti.com> X-Mailer: git-send-email 1.9.1 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160413_000222_028855_7554EBE1 X-CRM114-Status: UNSURE ( 9.59 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -7.9 (-------) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: j-keerthy@ti.com, linus.walleij@linaro.org, nsekhar@ti.com, linux-kernel@vger.kernel.org, t-kristo@ti.com, linux-gpio@vger.kernel.org, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-5.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP pcs_parse_bits_in_pinctrl_entry uses ffs which gives bit indices ranging from 1 to MAX. This leads to a corner case where we try to request the pin number = MAX and fails. bit_pos value is being calculted using ffs. pin_num_from_lsb uses bit_pos value. pins array is populated with: pin + pin_num_from_lsb. The above is 1 more than usual bit indices as bit_pos uses ffs to compute first set bit. Hence the last of the pins array is populated with the MAX value and not MAX - 1 which causes error when we call pin_request. mask_pos is rightly calculated as ((pcs->fmask) << (bit_pos - 1)) Consequently val_pos and submask are correct. Hence use __ffs which gives (ffs(x) - 1) as the first bit set. fixes: 4e7e8017a8 ("pinctrl: pinctrl-single: enhance to configure multiple pins of different modules") Signed-off-by: Keerthy --- Boot tested on da850-evm drivers/pinctrl/pinctrl-single.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c index 748c047..897b89b 100644 --- a/drivers/pinctrl/pinctrl-single.c +++ b/drivers/pinctrl/pinctrl-single.c @@ -1323,9 +1323,9 @@ static int pcs_parse_bits_in_pinctrl_entry(struct pcs_device *pcs, /* Parse pins in each row from LSB */ while (mask) { - bit_pos = ffs(mask); + bit_pos = __ffs(mask); pin_num_from_lsb = bit_pos / pcs->bits_per_pin; - mask_pos = ((pcs->fmask) << (bit_pos - 1)); + mask_pos = ((pcs->fmask) << bit_pos); val_pos = val & mask_pos; submask = mask & mask_pos;