From patchwork Mon Jun 18 08:12:43 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 10470449 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 7CA6A600CC for ; Mon, 18 Jun 2018 09:30:50 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6EEC5288D7 for ; Mon, 18 Jun 2018 09:30:50 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 62FF828987; Mon, 18 Jun 2018 09:30:50 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 082A8288D7 for ; Mon, 18 Jun 2018 09:30:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935799AbeFRJad (ORCPT ); Mon, 18 Jun 2018 05:30:33 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:56202 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932792AbeFRIZL (ORCPT ); Mon, 18 Jun 2018 04:25:11 -0400 Received: from localhost (LFbn-1-12247-202.w90-92.abo.wanadoo.fr [90.92.61.202]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 1070FBAD; Mon, 18 Jun 2018 08:25:11 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexander Graf , Marc Zyngier , Mark Brown , Eric Anholt , Stefan Wahren , Florian Fainelli , Ray Jui , Scott Branden , bcm-kernel-feedback-list@broadcom.com, linux-spi@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org, Rob Herring , Sasha Levin Subject: [PATCH 4.16 178/279] spi: bcm2835aux: ensure interrupts are enabled for shared handler Date: Mon, 18 Jun 2018 10:12:43 +0200 Message-Id: <20180618080616.307818426@linuxfoundation.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180618080608.851973560@linuxfoundation.org> References: <20180618080608.851973560@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Rob Herring [ Upstream commit bc519d9574618e47a0c788000fb78da95e18d953 ] The BCM2835 AUX SPI has a shared interrupt line (with AUX UART). Downstream fixes this with an AUX irqchip to demux the IRQ sources and a DT change which breaks compatibility with older kernels. The AUX irqchip was already rejected for upstream[1] and the DT change would break working systems if the DTB is updated to a newer one. The latter issue was brought to my attention by Alex Graf. The root cause however is a bug in the shared handler. Shared handlers must check that interrupts are actually enabled before servicing the interrupt. Add a check that the TXEMPTY or IDLE interrupts are enabled. [1] https://patchwork.kernel.org/patch/9781221/ Cc: Alexander Graf Cc: Marc Zyngier Cc: Mark Brown Cc: Eric Anholt Cc: Stefan Wahren Cc: Florian Fainelli Cc: Ray Jui Cc: Scott Branden Cc: bcm-kernel-feedback-list@broadcom.com Cc: linux-spi@vger.kernel.org Cc: linux-rpi-kernel@lists.infradead.org Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Rob Herring Reviewed-by: Eric Anholt Signed-off-by: Mark Brown Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/spi/spi-bcm2835aux.c | 5 +++++ 1 file changed, 5 insertions(+) -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html --- a/drivers/spi/spi-bcm2835aux.c +++ b/drivers/spi/spi-bcm2835aux.c @@ -184,6 +184,11 @@ static irqreturn_t bcm2835aux_spi_interr struct bcm2835aux_spi *bs = spi_master_get_devdata(master); irqreturn_t ret = IRQ_NONE; + /* IRQ may be shared, so return if our interrupts are disabled */ + if (!(bcm2835aux_rd(bs, BCM2835_AUX_SPI_CNTL1) & + (BCM2835_AUX_SPI_CNTL1_TXEMPTY | BCM2835_AUX_SPI_CNTL1_IDLE))) + return ret; + /* check if we have data to read */ while (bs->rx_len && (!(bcm2835aux_rd(bs, BCM2835_AUX_SPI_STAT) &