From patchwork Tue Apr 2 12:19:51 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Trent Piepho X-Patchwork-Id: 2377691 Return-Path: X-Original-To: patchwork-spi-devel-general@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from lists.sourceforge.net (lists.sourceforge.net [216.34.181.88]) by patchwork1.kernel.org (Postfix) with ESMTP id BDFD73FD8C for ; Tue, 2 Apr 2013 12:20:16 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=sfs-ml-4.v29.ch3.sourceforge.com) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1UN0CG-0001N3-F8; Tue, 02 Apr 2013 12:20:16 +0000 Received: from sog-mx-3.v43.ch3.sourceforge.com ([172.29.43.193] helo=mx.sourceforge.net) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1UN0CF-0001Mu-KJ for spi-devel-general@lists.sourceforge.net; Tue, 02 Apr 2013 12:20:15 +0000 Received-SPF: pass (sog-mx-3.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.220.41 as permitted sender) client-ip=209.85.220.41; envelope-from=tpiepho@gmail.com; helo=mail-pa0-f41.google.com; Received: from mail-pa0-f41.google.com ([209.85.220.41]) by sog-mx-3.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1UN0CE-0003TO-U5 for spi-devel-general@lists.sourceforge.net; Tue, 02 Apr 2013 12:20:15 +0000 Received: by mail-pa0-f41.google.com with SMTP id kx1so269025pab.14 for ; Tue, 02 Apr 2013 05:20:09 -0700 (PDT) X-Received: by 10.68.225.166 with SMTP id rl6mr23765227pbc.91.1364905209108; Tue, 02 Apr 2013 05:20:09 -0700 (PDT) Received: from localhost.localdomain (174-31-195-141.tukw.qwest.net. [174.31.195.141]) by mx.google.com with ESMTPS id f4sm1596359pbc.6.2013.04.02.05.20.07 (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 02 Apr 2013 05:20:08 -0700 (PDT) From: Trent Piepho To: linux-arm-kernel@lists.infradead.org, spi-devel-general@lists.sourceforge.net Subject: [PATCH V2 08/12] spi/mxs: Fix race in setup method Date: Tue, 2 Apr 2013 05:19:51 -0700 Message-Id: <1364905195-24286-8-git-send-email-tpiepho@gmail.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1364905195-24286-1-git-send-email-tpiepho@gmail.com> References: <1364905195-24286-1-git-send-email-tpiepho@gmail.com> X-Spam-Score: -1.6 (-) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -1.5 SPF_CHECK_PASS SPF reports sender host as permitted sender for sender-domain 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (tpiepho[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature X-Headers-End: 1UN0CE-0003TO-U5 Cc: Marek Vasut , Fabio Estevam , Trent Piepho , Shawn Guo X-BeenThere: spi-devel-general@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: Linux SPI core/device drivers discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: spi-devel-general-bounces@lists.sourceforge.net Despite many warnings in the SPI documentation and code, the spi-mxs driver sets shared chip registers in the ->setup method. This method can be called when transfers are in progress on other slaves controlled by the master. Setting registers or any other shared state will corrupt those transfers. So fix mxs_spi_setup() to not call mxs_spi_setup_transfer(). Signed-off-by: Trent Piepho Cc: Marek Vasut Cc: Fabio Estevam Cc: Shawn Guo --- drivers/spi/spi-mxs.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) diff --git a/drivers/spi/spi-mxs.c b/drivers/spi/spi-mxs.c index 103c478..2a2147a 100644 --- a/drivers/spi/spi-mxs.c +++ b/drivers/spi/spi-mxs.c @@ -115,21 +115,16 @@ static int mxs_spi_setup_transfer(struct spi_device *dev, static int mxs_spi_setup(struct spi_device *dev) { - int err = 0; - if (!dev->bits_per_word) dev->bits_per_word = 8; if (dev->mode & ~(SPI_CPOL | SPI_CPHA)) return -EINVAL; - err = mxs_spi_setup_transfer(dev, NULL); - if (err) { - dev_err(&dev->dev, - "Failed to setup transfer, error = %d\n", err); - } + if (dev->bits_per_word != 8) + return -EINVAL; - return err; + return 0; } static uint32_t mxs_spi_cs_to_reg(unsigned cs)