From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 806FEC2D0DB for ; Tue, 28 Jan 2020 14:14:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 546FA2468E for ; Tue, 28 Jan 2020 14:14:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580220868; bh=jV/dth03refcE4X+CD8qRfFQaEXuob2S/bnzO3uo3Fc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=HyUQseDt0b97dr55ye1jdRdJ07qcnAavJTL81mwpSv2n9MDzkG3J6ALRJN8jdRE+Q ol6lPejweROTJULpqftSsEjqyoEmfInDa5jaz6X4VGSRin2mMSyr0XWXmgHl4CjYoZ VwX9stgf3fCspH9zy6HAkyxiXUEsGSH/jYLs6ndY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729652AbgA1OO1 (ORCPT ); Tue, 28 Jan 2020 09:14:27 -0500 Received: from mail.kernel.org ([198.145.29.99]:36506 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729864AbgA1OOX (ORCPT ); Tue, 28 Jan 2020 09:14:23 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D07FF24694; Tue, 28 Jan 2020 14:14:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580220863; bh=jV/dth03refcE4X+CD8qRfFQaEXuob2S/bnzO3uo3Fc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IKbtprDHSUjl+teUz5iZyswqMAbB+SfEmR4W73inwAxiUrrphcfd2rDCPMoeKFyXd 9/4CvN36FrcOGy2ZDBwhxCnSMg5QDHTwPUdbs7x7K7g3Dlg7GdeCf+ZKcroiOiGXi0 7vK4YWECTNetIRFQqb/55lj2OD+Pg+iJpXqQZgg0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, =?UTF-8?q?Lars=20M=C3=B6llendorf?= , Lars-Peter Clausen , Stable@vger.kernel.org, Jonathan Cameron Subject: [PATCH 4.4 177/183] iio: buffer: align the size of scan bytes to size of the largest element Date: Tue, 28 Jan 2020 15:06:36 +0100 Message-Id: <20200128135847.434432262@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200128135829.486060649@linuxfoundation.org> References: <20200128135829.486060649@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Lars Möllendorf commit 883f616530692d81cb70f8a32d85c0d2afc05f69 upstream. Previous versions of `iio_compute_scan_bytes` only aligned each element to its own length (i.e. its own natural alignment). Because multiple consecutive sets of scan elements are buffered this does not work in case the computed scan bytes do not align with the natural alignment of the first scan element in the set. This commit fixes this by aligning the scan bytes to the natural alignment of the largest scan element in the set. Fixes: 959d2952d124 ("staging:iio: make iio_sw_buffer_preenable much more general.") Signed-off-by: Lars Möllendorf Reviewed-by: Lars-Peter Clausen Cc: Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/iio/industrialio-buffer.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -527,7 +527,7 @@ static int iio_compute_scan_bytes(struct { const struct iio_chan_spec *ch; unsigned bytes = 0; - int length, i; + int length, i, largest = 0; /* How much space will the demuxed element take? */ for_each_set_bit(i, mask, @@ -540,6 +540,7 @@ static int iio_compute_scan_bytes(struct length = ch->scan_type.storagebits / 8; bytes = ALIGN(bytes, length); bytes += length; + largest = max(largest, length); } if (timestamp) { ch = iio_find_channel_from_si(indio_dev, @@ -551,7 +552,10 @@ static int iio_compute_scan_bytes(struct length = ch->scan_type.storagebits / 8; bytes = ALIGN(bytes, length); bytes += length; + largest = max(largest, length); } + + bytes = ALIGN(bytes, largest); return bytes; }