From mboxrd@z Thu Jan 1 00:00:00 1970 From: Charles Keepax Subject: Re: [PATCH 2/2] i2c: Clear client->irq in i2c_device_remove Date: Thu, 10 Jan 2019 13:32:36 +0000 Message-ID: <20190110133236.GC3837@imbe.wolfsonmicro.main> References: <20181019085958.32694-1-ckeepax@opensource.cirrus.com> <20181019085958.32694-2-ckeepax@opensource.cirrus.com> <20190109214756.GA18115@jeknote.loshitsa1.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Content-Disposition: inline In-Reply-To: <20190109214756.GA18115@jeknote.loshitsa1.net> Sender: linux-kernel-owner@vger.kernel.org To: Yauhen Kharuzhy Cc: wsa@the-dreams.de, linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, patches@opensource.cirrus.com List-Id: linux-i2c@vger.kernel.org On Thu, Jan 10, 2019 at 12:47:56AM +0300, Yauhen Kharuzhy wrote: > On Fri, Oct 19, 2018 at 09:59:58AM +0100, Charles Keepax wrote: > > The IRQ will be mapped in i2c_device_probe only if client->irq is zero and > > i2c_device_remove does not clear this. When rebinding an I2C device, > > whos IRQ provider has also been rebound this means that an IRQ mapping > > will never be created, causing the I2C device to fail to acquire its > > IRQ. Fix this issue by clearing client->irq in i2c_device_remove, > > forcing i2c_device_probe to lookup the mapping again. > > Hi. > > I found driver i2c/busses/i2c-cht-wc.c which instantiates I2C device > (battery charger) and passes IRQ to driver not using standard I2C IRQ mapping code. > So if we reprobe I2C device (by reloading I2C device driver module or by > manipulations with sysfs), we get invalid IRQ number for client: > > adap->client_irq = irq_create_mapping(adap->irq_domain, 0); > ... > irq_set_chip_data(adap->client_irq, adap); > irq_set_chip_and_handler(adap->client_irq, &adap->irqchip, handle_simple_irq); > ... > board_info.irq = adap->client_irq; > adap->client = i2c_new_device(&adap->adapter, &board_info); > > > adap->client->irq will be reset after device removing here. > > > Any advice to fix this? Maybe move initial i2c_client->irq value to new field > like client->init_irq and copy it to client->irq at probing, for example? > Could you be a little more specific here, are you saying if you reprobe the battery charger device or if you reprobe the I2C controller itself? Apologies but I am having a little difficulty working out the path through which the IRQ is not reinitialised. As I would have through the battery chargers probe would have reset up the IRQ then the core would pick it up again from there. Thanks, Charles