From patchwork Wed Jan 28 12:23:54 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: 5728131 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 F11BCBF440 for ; Wed, 28 Jan 2015 12:30:03 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 1752A20259 for ; Wed, 28 Jan 2015 12:30:03 +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 2FC0720251 for ; Wed, 28 Jan 2015 12:30:02 +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 1YGRj0-0001pu-0A; Wed, 28 Jan 2015 12:28:02 +0000 Received: from merlin.infradead.org ([2001:4978:20e::2]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YGRfr-0005OU-Fu for linux-arm-kernel@bombadil.infradead.org; Wed, 28 Jan 2015 12:24:47 +0000 Received: from mail-la0-x233.google.com ([2a00:1450:4010:c03::233]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YGRfo-0000AR-K1 for linux-arm-kernel@lists.infradead.org; Wed, 28 Jan 2015 12:24:45 +0000 Received: by mail-la0-f51.google.com with SMTP id ge10so18699190lab.10 for ; Wed, 28 Jan 2015 04:24:16 -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=MVXA1DgxIbdz9XrYEdlGUaON6wqT6/Cl7lCIkMmLcz0=; b=PLRKx0ABa2NIqC67YSGT2ofZaMDFaE+kvo9xuG38efncECGFC02cmkkLi2+YMXBwLT 2ZfuveoaKwkaYvGKVHZg9PZCrD+RVnZ49qmB1Q7Dpr3+7Hv2+OzFwOdT03LZFUptRHCJ igqI/kLASk1MrFaXQP2c2SJrJwgotZhligTo4BppRbgsqQhjqoNTR3L1C9E+M6CEKu9m RpBUUe+IcYerkz++Kh5GX3SNnSio4Bs8UXV+U064DY+GotyCqJ4oPws29x5H5HXRczZu 5+H0XO5phbSJVNgEFJP1R37MeQMa4QhhHhqn6a6vQlbdDoyv2HcdSPgnYcVe/A+XaoB8 M6Jg== X-Received: by 10.153.5.35 with SMTP id cj3mr7631696lad.49.1422447856786; Wed, 28 Jan 2015 04:24:16 -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 xh7sm1293741lbb.17.2015.01.28.04.24.15 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 28 Jan 2015 04:24:15 -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 v2 15/15] spi/xilinx: Use polling mode on small transfers Date: Wed, 28 Jan 2015 13:23:54 +0100 Message-Id: <1422447834-23116-16-git-send-email-ricardo.ribalda@gmail.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1422447834-23116-1-git-send-email-ricardo.ribalda@gmail.com> References: <1422447834-23116-1-git-send-email-ricardo.ribalda@gmail.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150128_072444_828108_5535EE20 X-CRM114-Status: GOOD ( 16.37 ) X-Spam-Score: -2.7 (--) 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 Small transfers generally can be accomplished faster in polling mode. This patch select the transfer which size is bellow the buffer size to be done on polling mode Suggested-by: Mark Brown Signed-off-by: Ricardo Ribalda Delgado --- drivers/spi/spi-xilinx.c | 43 +++++++++++++++++++++++++------------------ 1 file changed, 25 insertions(+), 18 deletions(-) diff --git a/drivers/spi/spi-xilinx.c b/drivers/spi/spi-xilinx.c index 134d8cd..c6b0a6e 100644 --- a/drivers/spi/spi-xilinx.c +++ b/drivers/spi/spi-xilinx.c @@ -130,7 +130,6 @@ static void xilinx_spi_rx(struct xilinx_spi *xspi) static void xspi_init_hw(struct xilinx_spi *xspi) { void __iomem *regs_base = xspi->regs; - u32 inhibit; /* Reset the SPI device */ xspi->write_fn(XIPIF_V123B_RESET_MASK, @@ -140,22 +139,15 @@ static void xspi_init_hw(struct xilinx_spi *xspi) */ xspi->write_fn(XSPI_INTR_TX_EMPTY, regs_base + XIPIF_V123B_IIER_OFFSET); - /* Enable the global IPIF interrupt */ - if (xspi->irq >= 0) { - xspi->write_fn(XIPIF_V123B_GINTR_ENABLE, - regs_base + XIPIF_V123B_DGIER_OFFSET); - inhibit = XSPI_CR_TRANS_INHIBIT; - } else { - xspi->write_fn(0, regs_base + XIPIF_V123B_DGIER_OFFSET); - inhibit = 0; - } + /* Disable the global IPIF interrupt */ + xspi->write_fn(0, regs_base + XIPIF_V123B_DGIER_OFFSET); /* Deselect the slave on the SPI bus */ xspi->write_fn(0xffff, regs_base + XSPI_SSR_OFFSET); /* Disable the transmitter, enable Manual Slave Select Assertion, * put SPI controller into master mode, and enable it */ - xspi->write_fn(inhibit | XSPI_CR_MANUAL_SSELECT | - XSPI_CR_MASTER_MODE | XSPI_CR_ENABLE | XSPI_CR_TXFIFO_RESET | - XSPI_CR_RXFIFO_RESET, regs_base + XSPI_CR_OFFSET); + xspi->write_fn(XSPI_CR_MANUAL_SSELECT | XSPI_CR_MASTER_MODE | + XSPI_CR_ENABLE | XSPI_CR_TXFIFO_RESET | XSPI_CR_RXFIFO_RESET, + regs_base + XSPI_CR_OFFSET); } static void xilinx_spi_chipselect(struct spi_device *spi, int is_on) @@ -214,6 +206,8 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) { struct xilinx_spi *xspi = spi_master_get_devdata(spi->master); int remaining_words; /* the number of words left to transfer */ + bool use_irq = false; + u16 cr = 0; /* We get here with transmitter inhibited */ @@ -222,8 +216,20 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) remaining_words = t->len / xspi->bytes_per_word; reinit_completion(&xspi->done); + if (xspi->irq >= 0 && remaining_words > xspi->buffer_size) { + use_irq = true; + xspi->write_fn(XSPI_INTR_TX_EMPTY, + xspi->regs + XIPIF_V123B_IISR_OFFSET); + /* Enable the global IPIF interrupt */ + xspi->write_fn(XIPIF_V123B_GINTR_ENABLE, + xspi->regs + XIPIF_V123B_DGIER_OFFSET); + /* Inhibit irq to avoid spurious irqs on tx_empty*/ + cr = xspi->read_fn(xspi->regs + XSPI_CR_OFFSET); + xspi->write_fn(cr | XSPI_CR_TRANS_INHIBIT, + xspi->regs + XSPI_CR_OFFSET); + } + while (remaining_words) { - u16 cr = 0; int n_words, tx_words, rx_words; n_words = min(remaining_words, xspi->buffer_size); @@ -236,9 +242,7 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) * longer */ - if (xspi->irq >= 0) { - cr = xspi->read_fn(xspi->regs + XSPI_CR_OFFSET) & - ~XSPI_CR_TRANS_INHIBIT; + if (use_irq) { xspi->write_fn(cr, xspi->regs + XSPI_CR_OFFSET); wait_for_completion(&xspi->done); } else @@ -251,7 +255,7 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) * transmitter while the Isr refills the transmit register/FIFO, * or make sure it is stopped if we're done. */ - if (xspi->irq >= 0) + if (use_irq) xspi->write_fn(cr | XSPI_CR_TRANS_INHIBIT, xspi->regs + XSPI_CR_OFFSET); @@ -263,6 +267,9 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) remaining_words -= n_words; } + if (use_irq) + xspi->write_fn(0, xspi->regs + XIPIF_V123B_DGIER_OFFSET); + return t->len; }