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 17255C433E3 for ; Sat, 8 Aug 2020 23:50:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E0C3E206B5 for ; Sat, 8 Aug 2020 23:50:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596930605; bh=46yjb/k7TSnzZl7IjWeJ7jhtvXAOuNZPB8pbLl///So=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=JtsZX1KOMjnCh+PrcyWmv668te9GrrGHpQUIn7Mnr2G3h65dmYfEHQ9lT5sDhaVsZ IAVMVFMylld19WwO9QDirrcczWBqVcCpnmy2HjTrU+7mxmMd1HsxiQG0AhIBwESiWn n5vRdtYP400jXpf5k/o1q10JGg4H1N6PffEOBptU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726920AbgHHXuE (ORCPT ); Sat, 8 Aug 2020 19:50:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:49502 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727017AbgHHXgr (ORCPT ); Sat, 8 Aug 2020 19:36:47 -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 A4569206E9; Sat, 8 Aug 2020 23:36:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596929806; bh=46yjb/k7TSnzZl7IjWeJ7jhtvXAOuNZPB8pbLl///So=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=axxZqYC0w2HypduU9KFjmrXrMWuw5OXDXnLr05R3WSoOXM9fVkxOAnSNYNvPROEju +2snRG0TrkEvAG5PO0BelVa1OKS8WeMx0UcxJ1VLmly49WiTdmL8ttmoWswNiKP98u Wl10vksm6gGxbFiuMtdX59zpxX2QbKYROWTsIV54= 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 5.8 43/72] spi: lantiq: fix: Rx overflow error in full duplex mode Date: Sat, 8 Aug 2020 19:35:12 -0400 Message-Id: <20200808233542.3617339-43-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200808233542.3617339-1-sashal@kernel.org> References: <20200808233542.3617339-1-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 1fd7ee53d4510..44600fb71c484 100644 --- a/drivers/spi/spi-lantiq-ssc.c +++ b/drivers/spi/spi-lantiq-ssc.c @@ -184,6 +184,7 @@ 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) @@ -481,6 +482,7 @@ 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: @@ -509,6 +511,7 @@ static void tx_fifo_write(struct lantiq_ssc_spi *spi) lantiq_ssc_writel(spi, data, LTQ_SPI_TB); tx_free--; + spi->fdx_tx_level++; } } @@ -520,6 +523,13 @@ 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