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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1445BC00140 for ; Mon, 15 Aug 2022 21:36:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348631AbiHOVgv (ORCPT ); Mon, 15 Aug 2022 17:36:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34780 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243568AbiHOVfI (ORCPT ); Mon, 15 Aug 2022 17:35:08 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B884EA6C4E; Mon, 15 Aug 2022 12:24:54 -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 8FB0060EF0; Mon, 15 Aug 2022 19:24:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 96352C433D6; Mon, 15 Aug 2022 19:24:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660591493; bh=sDltwdfM+bb1xgm1e4fTojwxAiLFI29C+V8cwlFn1WA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NOeS+StV8Y+mfZuZ6SVS15FXm5S80etZkWlRFYZ1+2zWcem0LJVRW+a4bteP/WAJ3 qL3seBkbGtGXbrmoZIzjmWIlKaCI8ZzSDa6X+FMIcIwf66QfH+YluPtGHMmwYip6LB nruZ4N+sQ5Fu+acAiRdZnG3iX9BauGY5oiUy0WlE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jonathan Cameron , =?UTF-8?q?Nuno=20S=C3=A1?= , Sasha Levin Subject: [PATCH 5.18 0597/1095] iio: adc: ad7476: Fix alignment for DMA safety Date: Mon, 15 Aug 2022 19:59:56 +0200 Message-Id: <20220815180454.253495266@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220815180429.240518113@linuxfoundation.org> References: <20220815180429.240518113@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jonathan Cameron [ Upstream commit 58b74555afc8affe4ae4f57d396349158433fc80 ] ____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 that DMA safety 'may' require separate cachelines. Fixes tag is unlikely to be the actual introdution of the problem but is far enough back to cover any likely backporting. Fixes: 7a28fe3c93d6 ("staging:iio:ad7476: Squash driver into a single file.") Signed-off-by: Jonathan Cameron Acked-by: Nuno Sá Link: https://lore.kernel.org/r/20220508175712.647246-14-jic23@kernel.org Signed-off-by: Sasha Levin --- drivers/iio/adc/ad7476.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/iio/adc/ad7476.c b/drivers/iio/adc/ad7476.c index a1e8b32671cf..94776f696290 100644 --- a/drivers/iio/adc/ad7476.c +++ b/drivers/iio/adc/ad7476.c @@ -44,13 +44,12 @@ struct ad7476_state { struct spi_transfer xfer; 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 16 bit sample and one 64 bit * aligned 64 bit timestamp. */ - unsigned char data[ALIGN(2, sizeof(s64)) + sizeof(s64)] - ____cacheline_aligned; + unsigned char data[ALIGN(2, sizeof(s64)) + sizeof(s64)] __aligned(IIO_DMA_MINALIGN); }; enum ad7476_supported_device_ids { -- 2.35.1