From patchwork Sun May 8 17:55:57 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Jonathan Cameron X-Patchwork-Id: 12842544 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 7E0EFC43217 for ; Sun, 8 May 2022 19:11:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236540AbiEHTPE (ORCPT ); Sun, 8 May 2022 15:15:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38552 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237816AbiEHRzH (ORCPT ); Sun, 8 May 2022 13:55:07 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 88846DFEA for ; Sun, 8 May 2022 10:51:16 -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 23C4D6127D for ; Sun, 8 May 2022 17:51:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 66288C385AF; Sun, 8 May 2022 17:51:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1652032275; bh=hEXcEMT9BS9y3c87LTxYZOdwr4uQkb2dGrM1MthIEL8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=g3keH9D4z2+1F4Kf5NpL/bJsCgDGujJ598Sum5C7qBynOkf8q0h5yJ3PifanfVZhQ JxSaxPSDQZT+7nIyOu/+b+EeWMyoYQoe2Zj6kpiFtUkxKlWM0Dhivcs5PRM0yltsnt Nhhvi5N1GowwGcHd6EdrV2ks8R++CVXXv2lAyBXQkDhBLGX/Z6JPSirFAADHgEJqgI YuU7cpr92IAHhDxzq1bHmpniPHs3w9MvJW3ezKEWzVDKA4YmgxyxTd/GfMmC0iTHpd bTyKu92snKjSjj8GxRI6I7UcTyGxbpu2QCexpZvPr3lNy6/iE5qf0sHaLbpExD9BMu DCRD6o/PGJ65w== 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 17/92] iio: adc: ad7887: Fix alignment for DMA safety Date: Sun, 8 May 2022 18:55:57 +0100 Message-Id: <20220508175712.647246-18-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 tag is clearly not where this was introduced but it is very unlikely anyone will back port it past that point. Fixes: 65dd3d3d7a9b ("staging:iio:ad7887: Squash everything into one file") Signed-off-by: Jonathan Cameron Cc: Lars-Peter Clausen Acked-by: Nuno Sá --- drivers/iio/adc/ad7887.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/iio/adc/ad7887.c b/drivers/iio/adc/ad7887.c index f64999714a4d..965bdc8aa696 100644 --- a/drivers/iio/adc/ad7887.c +++ b/drivers/iio/adc/ad7887.c @@ -66,13 +66,12 @@ struct ad7887_state { unsigned char tx_cmd_buf[4]; /* - * DMA (thus cache coherency maintenance) requires the + * DMA (thus cache coherency maintenance) may require the * transfer buffers to live in their own cache lines. * Buffer needs to be large enough to hold two 16 bit samples and a * 64 bit aligned 64 bit timestamp. */ - unsigned char data[ALIGN(4, sizeof(s64)) + sizeof(s64)] - ____cacheline_aligned; + unsigned char data[ALIGN(4, sizeof(s64)) + sizeof(s64)] __aligned(IIO_DMA_MINALIGN); }; enum ad7887_supported_device_ids {