From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753470Ab3GIAVZ (ORCPT ); Mon, 8 Jul 2013 20:21:25 -0400 Received: from mail-pd0-f177.google.com ([209.85.192.177]:64046 "EHLO mail-pd0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753407Ab3GIAVY (ORCPT ); Mon, 8 Jul 2013 20:21:24 -0400 Message-ID: <1373329275.4223.1.camel@phoenix> Subject: [RFT][PATCH 1/2] irqchip: vt8500: Fix implementation for irq_ack and irq_mask From: Axel Lin To: Thomas Gleixner Cc: Tony Prisk , Alexey Charkov , linux-kernel@vger.kernel.org Date: Tue, 09 Jul 2013 08:21:15 +0800 Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.6.4-0ubuntu1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Current code sets both irq_ack and irq_mask callbacks to vt8500_irq_mask(). However, vt8500_irq_mask does not clear interrupt enable bit when the interrupt trigger mode is edge trigger. This patch moves the code clearing Interrupt Status Register bit to irq_ack(). irq_mask() always clear interrupt enable bit for all interrupt trigger mode. According to the datasheet, the Interrupt Status Register is written one to clear(Write 0 has no effect). So we don't need a read-modify-write operation for clearing a bit in interrupt status register. Signed-off-by: Axel Lin --- Hi Tony, I don't have the hardware to test, just found this issue while reading the code. I'd appreciate if you can review and test this patch serial. Thanks, Axel drivers/irqchip/irq-vt8500.c | 31 +++++++++++++++---------------- 1 file changed, 15 insertions(+), 16 deletions(-) diff --git a/drivers/irqchip/irq-vt8500.c b/drivers/irqchip/irq-vt8500.c index d970595..eb6d05a 100644 --- a/drivers/irqchip/irq-vt8500.c +++ b/drivers/irqchip/irq-vt8500.c @@ -81,25 +81,24 @@ struct vt8500_irq_data { static struct vt8500_irq_data intc[VT8500_INTC_MAX]; static u32 active_cnt = 0; -static void vt8500_irq_mask(struct irq_data *d) +static void vt8500_irq_ack(struct irq_data *d) { struct vt8500_irq_data *priv = d->domain->host_data; void __iomem *base = priv->base; void __iomem *stat_reg = base + VT8500_ICIS + (d->hwirq < 32 ? 0 : 4); - u8 edge, dctr; - u32 status; - - edge = readb(base + VT8500_ICDC + d->hwirq) & VT8500_EDGE; - if (edge) { - status = readl(stat_reg); - - status |= (1 << (d->hwirq & 0x1f)); - writel(status, stat_reg); - } else { - dctr = readb(base + VT8500_ICDC + d->hwirq); - dctr &= ~VT8500_INT_ENABLE; - writeb(dctr, base + VT8500_ICDC + d->hwirq); - } + + writel(1 << (d->hwirq & 0x1f), stat_reg); +} + +static void vt8500_irq_mask(struct irq_data *d) +{ + struct vt8500_irq_data *priv = d->domain->host_data; + void __iomem *base = priv->base; + u8 dctr; + + dctr = readb(base + VT8500_ICDC + d->hwirq); + dctr &= ~VT8500_INT_ENABLE; + writeb(dctr, base + VT8500_ICDC + d->hwirq); } static void vt8500_irq_unmask(struct irq_data *d) @@ -145,7 +144,7 @@ static int vt8500_irq_set_type(struct irq_data *d, unsigned int flow_type) static struct irq_chip vt8500_irq_chip = { .name = "vt8500", - .irq_ack = vt8500_irq_mask, + .irq_ack = vt8500_irq_ack, .irq_mask = vt8500_irq_mask, .irq_unmask = vt8500_irq_unmask, .irq_set_type = vt8500_irq_set_type, -- 1.8.1.2