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 67FE1EE0213 for ; Thu, 14 Sep 2023 01:55:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233979AbjINBz2 (ORCPT ); Wed, 13 Sep 2023 21:55:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58772 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233738AbjINBzV (ORCPT ); Wed, 13 Sep 2023 21:55:21 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 350831BEC; Wed, 13 Sep 2023 18:55:14 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 92AA6C43391; Thu, 14 Sep 2023 01:55:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1694656513; bh=mPNHzB+IFiOFsROhg18ge8hhu4lILId2aXwKB3Qc/g4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nxNVcvBWLpkDSppp9D9uPAYmLwVd25H04A6q4/UPKWYSK59YC435/U9W2A/+Yi4ER 6+je09OIRpFXs2Qd23u9Fr9buX5n1r4xzkk59Tguy6oKGWsSfwKbh1rIS0UfppoGlI z6NEuDpYl/vePkd6JAnhI0qnF/rSsocifirMv01ow8wCPv3EvnOagFqFD0oV6f+4i1 fLXRd9QOkfzIRx3+8YALtLOGFDxhcVoHKV0I1EihBIX9bY24PefR01Viovg4rlMe5e e6ZVyn7v1jSQA77Qa3sLoYf14a75qua5yltyhTysH9+F7ZmIm0MYSPmxQkvhtnuSAV LlHa2VxTRSM3g== 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 6.5 6/7] spi: sun6i: reduce DMA RX transfer width to single byte Date: Wed, 13 Sep 2023 21:54:50 -0400 Message-Id: <20230914015459.51740-6-sashal@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230914015459.51740-1-sashal@kernel.org> References: <20230914015459.51740-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.5.3 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 30d541612253e..8fcb2696ec099 100644 --- a/drivers/spi/spi-sun6i.c +++ b/drivers/spi/spi-sun6i.c @@ -207,7 +207,7 @@ 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