From patchwork Fri Jan 23 16:08:41 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: 5695991 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 158A09F358 for ; Fri, 23 Jan 2015 16:23:50 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 239E720145 for ; Fri, 23 Jan 2015 16:23:49 +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 218A8202E5 for ; Fri, 23 Jan 2015 16:23:48 +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 1YEgyX-0005aa-2T; Fri, 23 Jan 2015 16:20:49 +0000 Received: from mail-lb0-f179.google.com ([209.85.217.179]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YEgne-00034Z-8c for linux-arm-kernel@lists.infradead.org; Fri, 23 Jan 2015 16:09:38 +0000 Received: by mail-lb0-f179.google.com with SMTP id 10so6601756lbg.10 for ; Fri, 23 Jan 2015 08:09:08 -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=Bs/lCJ3DCSo2w3EA2LiFicRpic0ipiJ8/6p8btQtz1E=; b=1FCOhGGCO3qTYDFVdme6RPvwRLm//Hv+brY/eS+5xRjiRCcw3HK3UMGN6TYisDWoSG 6VHpAP3TC4y+DE3dIfgQHovaN7+xHdqi8RDwH/ucv9VZDjLk4BLV8apk3Whowmcap8Lu gb9G0c2wx0e2zgx4B0nymXdH60ixSR01AUogVfbgrdlIkOS71D8zW4nSo76WGXkJPvc+ u7bv52VqdPsnF1GkuSkma2P7UGMJjLFC4BDANnem91xMB2AwZNEFW0X/DcYgooPSfASA TzADOjdkqnuIvSk7Vham5uIa8XmmjfKcEl3V/RjAdeJ9Uy95SMBPL54dpMzofjB54GeS 0Ajg== X-Received: by 10.112.166.73 with SMTP id ze9mr8096892lbb.38.1422029348050; Fri, 23 Jan 2015 08:09:08 -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.41.2015.01.23.08.09.06 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 23 Jan 2015 08:09:07 -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 09/18] spi/xilinx: Do not inhibit transmission in polling mode Date: Fri, 23 Jan 2015 17:08:41 +0100 Message-Id: <1422029330-10971-10-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_080934_529042_43F5891B X-CRM114-Status: GOOD ( 13.17 ) 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 When no irq is used, there is no need to inhibit the transmission for every transaction. This inhibition was implemented to avoid a race condition with the irq handler. Signed-off-by: Ricardo Ribalda Delgado --- drivers/spi/spi-xilinx.c | 25 +++++++++++++++---------- 1 file changed, 15 insertions(+), 10 deletions(-) diff --git a/drivers/spi/spi-xilinx.c b/drivers/spi/spi-xilinx.c index 8a28cab..a70cb91 100644 --- a/drivers/spi/spi-xilinx.c +++ b/drivers/spi/spi-xilinx.c @@ -163,6 +163,7 @@ static void xspi_rx32(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, @@ -173,16 +174,19 @@ 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) + if (xspi->irq >= 0) { xspi->write_fn(XIPIF_V123B_GINTR_ENABLE, regs_base + XIPIF_V123B_DGIER_OFFSET); - else + inhibit = XSPI_CR_TRANS_INHIBIT; + } else { xspi->write_fn(0, regs_base + XIPIF_V123B_DGIER_OFFSET); + inhibit = 0; + } /* 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(XSPI_CR_TRANS_INHIBIT | XSPI_CR_MANUAL_SSELECT | + 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); } @@ -252,7 +256,7 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) reinit_completion(&xspi->done); while (xspi->remaining_bytes) { - u16 cr; + u16 cr = 0; int n_words; n_words = (xspi->remaining_bytes * 8) / xspi->bits_per_word; @@ -263,13 +267,13 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) /* Start the transfer by not inhibiting the transmitter any * longer */ - cr = xspi->read_fn(xspi->regs + XSPI_CR_OFFSET) & - ~XSPI_CR_TRANS_INHIBIT; - xspi->write_fn(cr, xspi->regs + XSPI_CR_OFFSET); - if (xspi->irq >= 0) + if (xspi->irq >= 0) { + cr = xspi->read_fn(xspi->regs + XSPI_CR_OFFSET) & + ~XSPI_CR_TRANS_INHIBIT; + xspi->write_fn(cr, xspi->regs + XSPI_CR_OFFSET); wait_for_completion(&xspi->done); - else + } else while (!(xspi->read_fn(xspi->regs + XSPI_SR_OFFSET) & XSPI_SR_TX_EMPTY_MASK)) ; @@ -279,7 +283,8 @@ 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. */ - xspi->write_fn(cr | XSPI_CR_TRANS_INHIBIT, + if (xspi->irq >= 0) + xspi->write_fn(cr | XSPI_CR_TRANS_INHIBIT, xspi->regs + XSPI_CR_OFFSET); /* Read out all the data from the Rx FIFO */