From patchwork Sun Sep 4 18:59:45 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robert Jarzmik X-Patchwork-Id: 9312747 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 C849960865 for ; Sun, 4 Sep 2016 19:02:29 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B73FC286C4 for ; Sun, 4 Sep 2016 19:02:29 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AB06228792; Sun, 4 Sep 2016 19:02:29 +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=-1.8 required=2.0 tests=BAYES_00,FREEMAIL_FROM, RCVD_IN_DNSWL_MED, RCVD_IN_SORBS_SPAM autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id F26C52877D for ; Sun, 4 Sep 2016 19:02:27 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bgcf1-0005PN-6V; Sun, 04 Sep 2016 19:00:55 +0000 Received: from smtp12.smtpout.orange.fr ([80.12.242.134] helo=smtp.smtpout.orange.fr) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bgceW-00044g-Hv for linux-arm-kernel@lists.infradead.org; Sun, 04 Sep 2016 19:00:27 +0000 Received: from belgarion.home ([109.222.86.9]) by mwinf5d23 with ME id fWzs1t00J0C5QSM03Wzt7C; Sun, 04 Sep 2016 20:59:58 +0200 X-ME-Helo: belgarion.home X-ME-Date: Sun, 04 Sep 2016 20:59:58 +0200 X-ME-IP: 109.222.86.9 From: Robert Jarzmik To: Russell King , Daniel Mack , Haojian Zhuang , Robert Jarzmik , Russell King - ARM Linux Subject: [PATCH 1/3] ARM: pxa: pxa_cplds: fix interrupt handling Date: Sun, 4 Sep 2016 20:59:45 +0200 Message-Id: <1473015587-15589-1-git-send-email-robert.jarzmik@free.fr> X-Mailer: git-send-email 2.1.4 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160904_120025_108937_FB3F9B14 X-CRM114-Status: GOOD ( 18.11 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Since its initial commit, the driver is buggy for multiple interrupts handling. The translation from the former lubbock.c file was not complete, and might stall all interrupt handling when multiple interrupts occur. This is especially true when inside the interrupt handler and if a new interrupt comes and is not handled, leaving the output line still held, and not creating a transition as the GPIO block behind would expect to trigger another cplds_irq_handler() call. For the record, the hardware is working as follows. The interrupt mechanism relies on : - one status register - one mask register Let's suppose the input irq lines are called : - i_sa1111 - i_lan91x - i_mmc_cd Let's suppose the status register for each irq line is called : - status_sa1111 - status_lan91x - status_mmc_cd Let's suppose the interrupt mask for each irq line is called : - irqen_sa1111 - irqen_lan91x - irqen_mmc_cd Let's suppose the output irq line, connected to GPIO0 is called : - o_gpio0 The behavior is as follows : - o_gpio0 = not((status_sa1111 & irqen_sa1111) | (status_lan91x & irqen_lan91x) | (status_mmc_cd & irqen_mmc_cd)) => this is a N-to-1 NOR gate and multiple AND gates - irqen_* is exactly as programmed by a write to the FPGA - status_* behavior is governed by a bi-stable D flip-flop => on next FPGA clock : - if i_xxx is high, status_xxx becomes 1 - if i_xxx is low, status_xxx remains as it is - if software sets status_xxx to 0, the D flip-flop is reset => status_xxx becomes 0 => on next FPGA clock cycle, if i_xxx is high, status_xxx becomes 1 again Fixes: fc9e38c0f4d3 ("ARM: pxa: lubbock: use new pxa_cplds driver") Reported-by: Russell King Signed-off-by: Robert Jarzmik --- arch/arm/mach-pxa/pxa_cplds_irqs.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) diff --git a/arch/arm/mach-pxa/pxa_cplds_irqs.c b/arch/arm/mach-pxa/pxa_cplds_irqs.c index 2385052b0ce1..e362f865fcd2 100644 --- a/arch/arm/mach-pxa/pxa_cplds_irqs.c +++ b/arch/arm/mach-pxa/pxa_cplds_irqs.c @@ -41,30 +41,35 @@ static irqreturn_t cplds_irq_handler(int in_irq, void *d) unsigned long pending; unsigned int bit; - pending = readl(fpga->base + FPGA_IRQ_SET_CLR) & fpga->irq_mask; - for_each_set_bit(bit, &pending, CPLDS_NB_IRQ) - generic_handle_irq(irq_find_mapping(fpga->irqdomain, bit)); + do { + pending = readl(fpga->base + FPGA_IRQ_SET_CLR) & fpga->irq_mask; + for_each_set_bit(bit, &pending, CPLDS_NB_IRQ) { + generic_handle_irq(irq_find_mapping(fpga->irqdomain, + bit)); + } + } while (pending); return IRQ_HANDLED; } -static void cplds_irq_mask_ack(struct irq_data *d) +static void cplds_irq_mask(struct irq_data *d) { struct cplds *fpga = irq_data_get_irq_chip_data(d); unsigned int cplds_irq = irqd_to_hwirq(d); - unsigned int set, bit = BIT(cplds_irq); + unsigned int bit = BIT(cplds_irq); fpga->irq_mask &= ~bit; writel(fpga->irq_mask, fpga->base + FPGA_IRQ_MASK_EN); - set = readl(fpga->base + FPGA_IRQ_SET_CLR); - writel(set & ~bit, fpga->base + FPGA_IRQ_SET_CLR); } static void cplds_irq_unmask(struct irq_data *d) { struct cplds *fpga = irq_data_get_irq_chip_data(d); unsigned int cplds_irq = irqd_to_hwirq(d); - unsigned int bit = BIT(cplds_irq); + unsigned int set, bit = BIT(cplds_irq); + + set = readl(fpga->base + FPGA_IRQ_SET_CLR); + writel(set & ~bit, fpga->base + FPGA_IRQ_SET_CLR); fpga->irq_mask |= bit; writel(fpga->irq_mask, fpga->base + FPGA_IRQ_MASK_EN); @@ -72,7 +77,8 @@ static void cplds_irq_unmask(struct irq_data *d) static struct irq_chip cplds_irq_chip = { .name = "pxa_cplds", - .irq_mask_ack = cplds_irq_mask_ack, + .irq_ack = cplds_irq_mask, + .irq_mask = cplds_irq_mask, .irq_unmask = cplds_irq_unmask, .flags = IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_SKIP_SET_WAKE, };