From patchwork Sun May 8 17:56:02 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Jonathan Cameron X-Patchwork-Id: 12842597 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EE14EC433EF for ; Sun, 8 May 2022 19:13:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230235AbiEHTR2 (ORCPT ); Sun, 8 May 2022 15:17:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38700 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239152AbiEHRzm (ORCPT ); Sun, 8 May 2022 13:55:42 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D3085DFEA for ; Sun, 8 May 2022 10:51:51 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 6F7506128D for ; Sun, 8 May 2022 17:51:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D95BEC385A4; Sun, 8 May 2022 17:51:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1652032310; bh=tWlXGj1wuhbxQvtR1Mb7vOtavNiKGCcLYoI2RtlXrhU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lWsXC1Bg2jTULojIgdP/Fqn4UcwEYF6cIWpSuX6uuxWPRMWiJDiP99Fdm8QVHMzct eLrKr3tF2msU3g9bnKHlIlVLxKxKdKgMTklnYlkAzgN4+YjpPcMx3tmqk/fYEGWf/k jgktb4tRjdB2LgjN8I3YhXZy1lQ17SFwXPsTjCY10V/Jrsbu9SjzHplPsNshacIv2v AmreqsMJ+g/xxAXiDrI0bSLlCtARW6Il5KLdfdHP+hRjZGg9bX9v4+oRftyOr6pmMy g1sp460sFiOLWuXBc5EaE5A04ZtPeDGJod9WhM32ylogDjaZjSisfGt6cTuaEVutsm NF4St5bkjXM7Q== From: Jonathan Cameron To: linux-iio@vger.kernel.org Cc: Alexandru Lazar , Akinobu Mita , Alexandru Tachici , Antoniu Miclaus , Charles-Antoine Couret , Cosmin Tanislav , David Lechner , Ivan Mikhaylov , Jacopo Mondi , Jean-Baptiste Maneyrol , Lars-Peter Clausen , Marcelo Schmitt , =?utf-8?q?M=C3=A5rten_Lindahl?= , Matt Ranostay , Matt Ranostay , Michael Hennerich , Michael Welling , Mugilraj Dhavachelvan , Navin Sankar Velliangiri , =?utf-8?q?Nuno_S=C3=A1?= , Paul Cercueil , Phil Reid , Puranjay Mohan , Ricardo Ribalda , Robert Jones , Rui Miguel Silva , Sean Nyekjaer , Tomas Melin , Tomislav Denis , =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= , Jonathan Cameron Subject: [PATCH v2 22/92] iio: adc: ltc2497: Fix alignment for DMA safety Date: Sun, 8 May 2022 18:56:02 +0100 Message-Id: <20220508175712.647246-23-jic23@kernel.org> X-Mailer: git-send-email 2.36.0 In-Reply-To: <20220508175712.647246-1-jic23@kernel.org> References: <20220508175712.647246-1-jic23@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org From: Jonathan Cameron ____cacheline_aligned is an insufficient guarantee for non-coherent DMA on platforms with 128 byte cachelines above L1. Switch to the updated IIO_DMA_MINALIGN definition. Update the comment to include 'may'. Fixes: bc82222fcca1 ("iio:adc: Driver for Linear Technology LTC2497 ADC") Signed-off-by: Jonathan Cameron Cc: Michael Hennerich Acked-by: Nuno Sá --- drivers/iio/adc/ltc2497.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/iio/adc/ltc2497.c b/drivers/iio/adc/ltc2497.c index 1adddf5a88a9..f7c786f37ceb 100644 --- a/drivers/iio/adc/ltc2497.c +++ b/drivers/iio/adc/ltc2497.c @@ -20,10 +20,10 @@ struct ltc2497_driverdata { struct ltc2497core_driverdata common_ddata; struct i2c_client *client; /* - * DMA (thus cache coherency maintenance) requires the + * DMA (thus cache coherency maintenance) may require the * transfer buffers to live in their own cache lines. */ - __be32 buf ____cacheline_aligned; + __be32 buf __aligned(IIO_DMA_MINALIGN); }; static int ltc2497_result_and_measure(struct ltc2497core_driverdata *ddata,