From patchwork Fri Jan 23 16:08:35 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ricardo Ribalda Delgado X-Patchwork-Id: 5695861 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 83BABC058D for ; Fri, 23 Jan 2015 16:17:19 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 571BA202AE for ; Fri, 23 Jan 2015 16:17:15 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 83D912028D for ; Fri, 23 Jan 2015 16:17:14 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1YEgsK-0007St-0V; Fri, 23 Jan 2015 16:14:24 +0000 Received: from mail-la0-x236.google.com ([2a00:1450:4010:c03::236]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YEgnR-0002wO-S0 for linux-arm-kernel@lists.infradead.org; Fri, 23 Jan 2015 16:09:31 +0000 Received: by mail-la0-f54.google.com with SMTP id hv19so8057492lab.13 for ; Fri, 23 Jan 2015 08:08:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=IslO5Db3Yk87R9i0CiKVMixFePKhFhkRvdNY5JNC7lk=; b=cYRa141c04hVNGRYQiF+3aMVPKrV5gprTe5WNKhpCdt8c9dwLyKYUBoRGHV0B6iy/C I2Fc7OLFdtK28YIZt+d7B/l3x7xTsP35GpPjcJCx3EhV8C/nTnvkfNz6+gl5Qar+N3Ue cU53BU/n21FYW3lbMhrhL4iyTQAYk0JXpn1cIQjPA63Q+sk33bh4HPIX6A3YZhCA+9nJ LXbKZxK0gbdJmQ8mxkwjLP7b3+D2bpDULLD9OUFXq8fiYrYwkyNiwSKOc2I7ZZoWxvCA bc10hribNsa1M34b4b2twNAbd/CzuXuX2zisuLqUAbbXKIFYAu2H71YzJ23XJuY2j4I6 d6Pw== X-Received: by 10.152.43.103 with SMTP id v7mr8163923lal.29.1422029338466; Fri, 23 Jan 2015 08:08:58 -0800 (PST) Received: from neopili.qtec.com (cpe.xe-3-0-1-778.vbrnqe10.dk.customer.tdc.net. [80.197.57.18]) by mx.google.com with ESMTPSA id h7sm542990lbl.41.2015.01.23.08.08.57 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 23 Jan 2015 08:08:57 -0800 (PST) From: Ricardo Ribalda Delgado To: Mark Brown , Michal Simek , =?UTF-8?q?S=C3=B6ren=20Brinkmann?= , linux-spi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH 03/18] spi/xilinx: Simplify data read from the Rx FIFO Date: Fri, 23 Jan 2015 17:08:35 +0100 Message-Id: <1422029330-10971-4-git-send-email-ricardo.ribalda@gmail.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1422029330-10971-1-git-send-email-ricardo.ribalda@gmail.com> References: <1422029330-10971-1-git-send-email-ricardo.ribalda@gmail.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150123_080922_163570_B209A4FA X-CRM114-Status: GOOD ( 13.30 ) X-Spam-Score: -0.8 (/) Cc: Ricardo Ribalda Delgado X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.1 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_MED, T_DKIM_INVALID, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The number of words in the read buffer will be exactly the same as the number of words written on write buffer, once the transaction has finished. Instead of cheking the rx_empty flags for every word simply save the number of words written by fill_tx_fifo. Signed-off-by: Ricardo Ribalda Delgado --- drivers/spi/spi-xilinx.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/drivers/spi/spi-xilinx.c b/drivers/spi/spi-xilinx.c index e1d9a20..416b227 100644 --- a/drivers/spi/spi-xilinx.c +++ b/drivers/spi/spi-xilinx.c @@ -221,9 +221,10 @@ static int xilinx_spi_setup_transfer(struct spi_device *spi, return 0; } -static void xilinx_spi_fill_tx_fifo(struct xilinx_spi *xspi) +static int xilinx_spi_fill_tx_fifo(struct xilinx_spi *xspi) { u8 sr; + int n_words = 0; /* Fill the Tx FIFO with as many bytes as possible */ sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET); @@ -234,7 +235,10 @@ static void xilinx_spi_fill_tx_fifo(struct xilinx_spi *xspi) xspi->write_fn(0, xspi->regs + XSPI_TXD_OFFSET); xspi->remaining_bytes -= xspi->bits_per_word / 8; sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET); + n_words++; } + + return n_words; } static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) @@ -259,9 +263,9 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) for (;;) { u16 cr; - u8 sr; + int n_words; - xilinx_spi_fill_tx_fifo(xspi); + n_words = xilinx_spi_fill_tx_fifo(xspi); /* Start the transfer by not inhibiting the transmitter any * longer @@ -282,11 +286,8 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) xspi->regs + XSPI_CR_OFFSET); /* Read out all the data from the Rx FIFO */ - sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET); - while ((sr & XSPI_SR_RX_EMPTY_MASK) == 0) { + while (n_words--) xspi->rx_fn(xspi); - sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET); - } /* See if there is more data to send */ if (xspi->remaining_bytes <= 0)