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 E6E56EE021F for ; Thu, 14 Sep 2023 02:11:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233628AbjINCLz (ORCPT ); Wed, 13 Sep 2023 22:11:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60678 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234105AbjINBzz (ORCPT ); Wed, 13 Sep 2023 21:55:55 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 93F481FF9; Wed, 13 Sep 2023 18:55:41 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E6A5DC433C8; Thu, 14 Sep 2023 01:55:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1694656541; bh=gXVhJOHHu42wAbkHvrobBuAxMZhcTwxM0j4OPJEY6D0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qG71OHQbCaL+Ti3zHuIzIPYGVRd66+PjwUbFGa3ApuSX6nVQebACo4fUqJs0KEp4Z k+SkH3r8R4IK5c+6DmKI0Oy8BkmjmALWRqYHgJIctNuxwnDCCkY9PBfvpq/gxwUuYG AiAw1Ko4OfmWKqTy7Z3xvcpEuKiS/wLUa9yQR6HE7Wk9CMcvNbgwDBfi17MVEnnBLd vRjI+C2IFMh27iM4FQCDBZCP9krp8XsWFrYpnjIED2Tmbrqpzm+uGHZ44fBRWf+qVc 6FJJDqOs2x5c1GyaaXM2wNhB9WGfmmP5wVdf7QbqdpHzrYPfaWx0aTMQ6f0uqGSxEF B4vsSPIPxQSLA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Tobias Schramm , Mark Brown , Sasha Levin , wens@csie.org, jernej.skrabec@gmail.com, samuel@sholland.org, linux-spi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev Subject: [PATCH AUTOSEL 5.15 2/3] spi: sun6i: reduce DMA RX transfer width to single byte Date: Wed, 13 Sep 2023 21:55:35 -0400 Message-Id: <20230914015536.51984-2-sashal@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230914015536.51984-1-sashal@kernel.org> References: <20230914015536.51984-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.15.131 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Tobias Schramm [ Upstream commit 171f8a49f212e87a8b04087568e1b3d132e36a18 ] Through empirical testing it has been determined that sometimes RX SPI transfers with DMA enabled return corrupted data. This is down to single or even multiple bytes lost during DMA transfer from SPI peripheral to memory. It seems the RX FIFO within the SPI peripheral can become confused when performing bus read accesses wider than a single byte to it during an active SPI transfer. This patch reduces the width of individual DMA read accesses to the RX FIFO to a single byte to mitigate that issue. Signed-off-by: Tobias Schramm Link: https://lore.kernel.org/r/20230827152558.5368-2-t.schramm@manjaro.org Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- drivers/spi/spi-sun6i.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c index 23ad052528dbe..2bfe87873edb3 100644 --- a/drivers/spi/spi-sun6i.c +++ b/drivers/spi/spi-sun6i.c @@ -200,7 +200,7 @@ static int sun6i_spi_prepare_dma(struct sun6i_spi *sspi, struct dma_slave_config rxconf = { .direction = DMA_DEV_TO_MEM, .src_addr = sspi->dma_addr_rx, - .src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES, + .src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE, .src_maxburst = 8, }; -- 2.40.1