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 X-Spam-Level: X-Spam-Status: No, score=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A1470C433E0 for ; Sat, 8 Aug 2020 23:41:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7014E2053B for ; Sat, 8 Aug 2020 23:41:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596930101; bh=XJ5DmlNOlYa9O5RhsrLNP3SNVFa/vv5QstJP+KMrTms=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=fHKkgVfRkBDiFTwCpL1xs1GjTbCxCe5Bsc9ZDl1agmh006urhY+vTLmDfrU24CLwn h726lwCt2lPHnxZsOSnV7ZCVj8NvTWuz5KZNPYzdpYMATZKOZm97KwTl7uvYFjM9Ak uN/AT5ZU6+OIFSlHXbkENgadgeI5Zzd1AnWoeWnk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728858AbgHHXkh (ORCPT ); Sat, 8 Aug 2020 19:40:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:56166 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728849AbgHHXkf (ORCPT ); Sat, 8 Aug 2020 19:40:35 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5EC3D2053B; Sat, 8 Aug 2020 23:40:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596930035; bh=XJ5DmlNOlYa9O5RhsrLNP3SNVFa/vv5QstJP+KMrTms=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VqD03Tx7WPbgBxDwJ+Eu3VodgO30yISANf5txeEwNmNlcXSVgleKlUsPBvZZCiz8Q 3qAs//9TFw5SD3Gb6Clh9+2saHKm9+qKWWk1qQeKw1L82+PHhqlIirRI/jHmQfhiQD Ff/iUeOrz+Nv+MGexhlHOo/fnADxKHn++cD5rQ4Y= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Dilip Kota , Mark Brown , Sasha Levin , linux-spi@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 13/14] spi: lantiq: fix: Rx overflow error in full duplex mode Date: Sat, 8 Aug 2020 19:40:12 -0400 Message-Id: <20200808234013.3619541-13-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200808234013.3619541-1-sashal@kernel.org> References: <20200808234013.3619541-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org From: Dilip Kota [ Upstream commit 661ccf2b3f1360be50242726f7c26ced6a9e7d52 ] In full duplex mode, rx overflow error is observed. To overcome the error, wait until the complete data got received and proceed further. Fixes: 17f84b793c01 ("spi: lantiq-ssc: add support for Lantiq SSC SPI controller") Signed-off-by: Dilip Kota Link: https://lore.kernel.org/r/efb650b0faa49a00788c4e0ca8ef7196bdba851d.1594957019.git.eswara.kota@linux.intel.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- drivers/spi/spi-lantiq-ssc.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/spi/spi-lantiq-ssc.c b/drivers/spi/spi-lantiq-ssc.c index d5976615d924b..dc740b5f720ba 100644 --- a/drivers/spi/spi-lantiq-ssc.c +++ b/drivers/spi/spi-lantiq-ssc.c @@ -187,6 +187,7 @@ struct lantiq_ssc_spi { unsigned int tx_fifo_size; unsigned int rx_fifo_size; unsigned int base_cs; + unsigned int fdx_tx_level; }; static u32 lantiq_ssc_readl(const struct lantiq_ssc_spi *spi, u32 reg) @@ -484,6 +485,7 @@ static void tx_fifo_write(struct lantiq_ssc_spi *spi) u32 data; unsigned int tx_free = tx_fifo_free(spi); + spi->fdx_tx_level = 0; while (spi->tx_todo && tx_free) { switch (spi->bits_per_word) { case 2 ... 8: @@ -512,6 +514,7 @@ static void tx_fifo_write(struct lantiq_ssc_spi *spi) lantiq_ssc_writel(spi, data, LTQ_SPI_TB); tx_free--; + spi->fdx_tx_level++; } } @@ -523,6 +526,13 @@ static void rx_fifo_read_full_duplex(struct lantiq_ssc_spi *spi) u32 data; unsigned int rx_fill = rx_fifo_level(spi); + /* + * Wait until all expected data to be shifted in. + * Otherwise, rx overrun may occur. + */ + while (rx_fill != spi->fdx_tx_level) + rx_fill = rx_fifo_level(spi); + while (rx_fill) { data = lantiq_ssc_readl(spi, LTQ_SPI_RB); -- 2.25.1