From patchwork Fri Jul 17 06:27:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dilip Kota X-Patchwork-Id: 11669137 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1576A1392 for ; Fri, 17 Jul 2020 06:30:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EDA3A21744 for ; Fri, 17 Jul 2020 06:30:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726233AbgGQGaa (ORCPT ); Fri, 17 Jul 2020 02:30:30 -0400 Received: from mga18.intel.com ([134.134.136.126]:10212 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726056AbgGQGaa (ORCPT ); Fri, 17 Jul 2020 02:30:30 -0400 IronPort-SDR: Cfx5WmuYM9d2CALIgsoPKeGdVAifmtHr4orAdr/19dKEZWDkAlDida8DQKwWMaHyh6CyenHfLa 69yWP5H7coKw== X-IronPort-AV: E=McAfee;i="6000,8403,9684"; a="137006242" X-IronPort-AV: E=Sophos;i="5.75,362,1589266800"; d="scan'208";a="137006242" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Jul 2020 23:30:29 -0700 IronPort-SDR: UstrEUAEOS5WbWF6+q1Dv4sbthHyr85FF7NRBvh50qLVkVm2uqWqeqVXa6CqDcG0sPfguSkryb zufQbxwUEmqA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,362,1589266800"; d="scan'208";a="269458022" Received: from sgsxdev004.isng.intel.com (HELO localhost) ([10.226.88.13]) by fmsmga007.fm.intel.com with ESMTP; 16 Jul 2020 23:30:26 -0700 From: Dilip Kota To: broonie@kernel.org, robh@kernel.org, linux-spi@vger.kernel.org, devicetree@vger.kernel.org Cc: linux-kernel@vger.kernel.org, daniel.schwierzeck@gmail.com, hauke@hauke-m.de, andriy.shevchenko@intel.com, cheol.yong.kim@intel.com, chuanhua.lei@linux.intel.com, qi-ming.wu@intel.com, Dilip Kota Subject: [PATCH v2 1/8] spi: lantiq: fix: Rx overflow error in full duplex mode Date: Fri, 17 Jul 2020 14:27:50 +0800 Message-Id: X-Mailer: git-send-email 2.11.0 Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org 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 --- 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);