From patchwork Sun May 8 17:55:55 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Jonathan Cameron X-Patchwork-Id: 12842673 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 B89A7C3527C for ; Sun, 8 May 2022 19:17:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231701AbiEHTTL (ORCPT ); Sun, 8 May 2022 15:19:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38482 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239131AbiEHRyy (ORCPT ); Sun, 8 May 2022 13:54:54 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 301BDDFEA for ; Sun, 8 May 2022 10:51:03 -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 ams.source.kernel.org (Postfix) with ESMTPS id D8B98B80E5A for ; Sun, 8 May 2022 17:51:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8B4A7C385AC; Sun, 8 May 2022 17:50:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1652032260; bh=7poQt62uyyjesDBCqWDoCRnX0ieZPq/3A0F835iY2pQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TwF2qfGuTe9lTlNFCGom9Se6OiEAZcsmgccsWavmE9GYqHflqIZ6sc5fu9PLKtKC6 I6uPDkf0T4I2s6Fh/iiYp3A+TqNed+MIua5pOiu4C2s/6Pq1PwGarZ2JzZ9Cw4LTfh hMuOh4IobpA632vH78KfSEygU33iCNiE+MapU9L6FKCJLrT/w8PEzGSoSXFf4Rr3t/ sgRCgmF1DY78v3S36an101rZM7jF9l98wZBNAx5aKBBpOzn/TgaieoH8ap6Z5nOzte IPQx9iPND/gJ76V5RWe9rWahEodKfMIvj9wrxuR61Ut+H9oEiTMWqt7l8uP5UVRhKb kKxW2LfVX0rdw== 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 15/92] iio: adc: ad7766: Fix alignment for DMA safety Date: Sun, 8 May 2022 18:55:55 +0100 Message-Id: <20220508175712.647246-16-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 reflect the fact DMA safety 'may' require separate cachelines. Fixes: aa16c6bd0e09 ("iio:adc: Add support for AD7766/AD7767") Signed-off-by: Jonathan Cameron Cc: Lars-Peter Clausen Acked-by: Nuno Sá --- drivers/iio/adc/ad7766.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/iio/adc/ad7766.c b/drivers/iio/adc/ad7766.c index 51ee9482e0df..3079a0872947 100644 --- a/drivers/iio/adc/ad7766.c +++ b/drivers/iio/adc/ad7766.c @@ -45,13 +45,12 @@ struct ad7766 { struct spi_message msg; /* - * DMA (thus cache coherency maintenance) requires the + * DMA (thus cache coherency maintenance) may require the * transfer buffers to live in their own cache lines. * Make the buffer large enough for one 24 bit sample and one 64 bit * aligned 64 bit timestamp. */ - unsigned char data[ALIGN(3, sizeof(s64)) + sizeof(s64)] - ____cacheline_aligned; + unsigned char data[ALIGN(3, sizeof(s64)) + sizeof(s64)] __aligned(IIO_DMA_MINALIGN); }; /*