From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752557AbdHTBoY (ORCPT ); Sat, 19 Aug 2017 21:44:24 -0400 Received: from mx2.suse.de ([195.135.220.15]:33484 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752440AbdHTBoX (ORCPT ); Sat, 19 Aug 2017 21:44:23 -0400 Subject: Re: [RFC 3/3] irqchip: Add Realtek RTD1295 mux driver To: linux-arm-kernel@lists.infradead.org, linux-clk Cc: Thomas Gleixner , Jason Cooper , Marc Zyngier , =?UTF-8?B?6JKL5Li955C0?= , linux-kernel@vger.kernel.org, Roc He References: <20170817101140.32000-1-afaerber@suse.de> <20170817101140.32000-4-afaerber@suse.de> From: =?UTF-8?Q?Andreas_F=c3=a4rber?= Organization: SUSE Linux GmbH Message-ID: <32b536aa-36df-33fc-36f0-da974e480fea@suse.de> Date: Sun, 20 Aug 2017 03:44:20 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <20170817101140.32000-4-afaerber@suse.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 17.08.2017 um 12:11 schrieb Andreas Färber: > This irq mux driver is derived from the RTD1295 vendor DT and assumes a linear > mapping between intr_en and intr_status registers. Code for RTD119x indicates > this may not always be the case (i2c_3). > > The register initialization was copied from QNAP's mach-rtk119x/rtk_irq_mux.c > as a boot fix, without full insights into what exactly this is changing (TODO). > > Signed-off-by: Andreas Färber [...] > diff --git a/drivers/irqchip/irq-rtd119x-mux.c b/drivers/irqchip/irq-rtd119x-mux.c > new file mode 100644 > index 000000000000..c6c1ba126bf3 > --- /dev/null > +++ b/drivers/irqchip/irq-rtd119x-mux.c [...] > +static int __init rtd119x_irq_mux_init(struct device_node *node, > + struct device_node *parent, > + const struct rtd119x_irq_mux_info *info) > +{ > + struct rtd119x_irq_mux_data *data; > + void __iomem *base; > + u32 val; [...] > + /* TODO Investigate why these are necessary (from downstream rtk119x rtk_irq_mux.c) */ > + val = readl(data->intr_en); > + val &= ~BIT(2); > + writel(val, data->intr_en); > + > + writel(BIT(2), data->intr_status); This intr_status write appears to be the fix. The register is 0x00000004 before, but oddly writing it again resolves the observed timer hang. The intr_en register is 0xe0183924 before, and masking out bit 2 makes no observable difference. > + > + irq_set_chained_handler_and_data(data->irq, rtd119x_mux_irq_handle, data); > + > + return 0; > +} [snip] Regards, Andreas -- SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg)