From patchwork Thu Jun 15 13:59:31 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Phil Reid X-Patchwork-Id: 9788919 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 1C848602CB for ; Thu, 15 Jun 2017 14:06:36 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0E22C28415 for ; Thu, 15 Jun 2017 14:06:36 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 02CF2285B3; Thu, 15 Jun 2017 14:06:35 +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=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham 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 66CC928415 for ; Thu, 15 Jun 2017 14:06:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752116AbdFOOGa (ORCPT ); Thu, 15 Jun 2017 10:06:30 -0400 Received: from anchovy3.45ru.net.au ([203.30.46.155]:59459 "EHLO anchovy.45ru.net.au" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751976AbdFOOG3 (ORCPT ); Thu, 15 Jun 2017 10:06:29 -0400 X-Greylist: delayed 400 seconds by postgrey-1.27 at vger.kernel.org; Thu, 15 Jun 2017 10:06:28 EDT Received: (qmail 19465 invoked by uid 5089); 15 Jun 2017 13:59:46 -0000 Received: by simscan 1.2.0 ppid: 19326, pid: 19329, t: 0.1668s scanners: regex: 1.2.0 attach: 1.2.0 clamav: 0.88.3/m:40/d:1950 X-RBL: $rbltext Received: from unknown (HELO preid-centos7.electromag.com.au) (preid@electromag.com.au@114.30.119.20) by anchovy2.45ru.net.au with ESMTPA; 15 Jun 2017 13:59:45 -0000 Received: by preid-centos7.electromag.com.au (Postfix, from userid 1000) id 8D2D83026171F; Thu, 15 Jun 2017 21:59:41 +0800 (AWST) From: Phil Reid To: wsa@the-dreams.de, robh+dt@kernel.org, mark.rutland@arm.com, sre@kernel.org, jdelvare@suse.com, jglauber@cavium.com, david.daney@cavium.com, peda@axentia.se, preid@electromag.com.au, linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, linux-pm@vger.kernel.org Subject: [PATCH v7 03/10] i2c: i2c-smbus: Use threaded irq for smbalert Date: Thu, 15 Jun 2017 21:59:31 +0800 Message-Id: <1497535178-12001-4-git-send-email-preid@electromag.com.au> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1497535178-12001-1-git-send-email-preid@electromag.com.au> References: <1497535178-12001-1-git-send-email-preid@electromag.com.au> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Prior to this commit the smbalert_irq was handling in the hard irq context. This change switch to using a thread irq which avoids the need for the work thread. Using threaded irq also removes the need for the edge_triggered flag as the enabling / disabling of the hard irq for level triggered interrupts will be handled by the irq core. Without this change have an irq connected to something like an i2c gpio resulted in a null ptr deferences. Specifically handle_nested_irq calls the threaded irq handler. There are currently 3 in tree drivers affected by this change. i2c-parport driver calls i2c_handle_smbus_alert in a hard irq context. This driver use edge trigger interrupts which skip the enable / disable calls. But it still need to handle the smbus transaction on a thread. So the work thread is kept for this driver. i2c-parport-light & i2c-thunderx-pcidrv provide the irq number in the setup which will result in the thread irq being used. i2c-parport-light is edge trigger so the enable / disable call was skipped as well. i2c-thunderx-pcidrv is getting the edge / level trigger setting from of data and was setting the flag as required. However the irq core should handle this automatically. Signed-off-by: Phil Reid Reviewed-by: Benjamin Tissoires --- drivers/i2c/busses/i2c-parport-light.c | 1 - drivers/i2c/busses/i2c-parport.c | 1 - drivers/i2c/busses/i2c-thunderx-pcidrv.c | 6 ----- drivers/i2c/i2c-smbus.c | 41 +++++++++++++------------------- include/linux/i2c-smbus.h | 1 - 5 files changed, 17 insertions(+), 33 deletions(-) diff --git a/drivers/i2c/busses/i2c-parport-light.c b/drivers/i2c/busses/i2c-parport-light.c index 1bcdd10..e6e22b8 100644 --- a/drivers/i2c/busses/i2c-parport-light.c +++ b/drivers/i2c/busses/i2c-parport-light.c @@ -123,7 +123,6 @@ static int parport_getsda(void *data) /* SMBus alert support */ static struct i2c_smbus_alert_setup alert_data = { - .alert_edge_triggered = 1, }; static struct i2c_client *ara; static struct lineop parport_ctrl_irq = { diff --git a/drivers/i2c/busses/i2c-parport.c b/drivers/i2c/busses/i2c-parport.c index a8e54df..319209a 100644 --- a/drivers/i2c/busses/i2c-parport.c +++ b/drivers/i2c/busses/i2c-parport.c @@ -237,7 +237,6 @@ static void i2c_parport_attach(struct parport *port) /* Setup SMBus alert if supported */ if (adapter_parm[type].smbus_alert) { - adapter->alert_data.alert_edge_triggered = 1; adapter->ara = i2c_setup_smbus_alert(&adapter->adapter, &adapter->alert_data); if (adapter->ara) diff --git a/drivers/i2c/busses/i2c-thunderx-pcidrv.c b/drivers/i2c/busses/i2c-thunderx-pcidrv.c index 1d4c2be..c27a50f 100644 --- a/drivers/i2c/busses/i2c-thunderx-pcidrv.c +++ b/drivers/i2c/busses/i2c-thunderx-pcidrv.c @@ -112,8 +112,6 @@ static void thunder_i2c_clock_disable(struct device *dev, struct clk *clk) static int thunder_i2c_smbus_setup_of(struct octeon_i2c *i2c, struct device_node *node) { - u32 type; - if (!node) return -EINVAL; @@ -121,10 +119,6 @@ static int thunder_i2c_smbus_setup_of(struct octeon_i2c *i2c, if (!i2c->alert_data.irq) return -EINVAL; - type = irqd_get_trigger_type(irq_get_irq_data(i2c->alert_data.irq)); - i2c->alert_data.alert_edge_triggered = - (type & IRQ_TYPE_LEVEL_MASK) ? 1 : 0; - i2c->ara = i2c_setup_smbus_alert(&i2c->adap, &i2c->alert_data); if (!i2c->ara) return -ENODEV; diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c index f9271c7..d4af270 100644 --- a/drivers/i2c/i2c-smbus.c +++ b/drivers/i2c/i2c-smbus.c @@ -25,8 +25,6 @@ #include struct i2c_smbus_alert { - unsigned int alert_edge_triggered:1; - int irq; struct work_struct alert; struct i2c_client *ara; /* Alert response address */ }; @@ -72,13 +70,12 @@ static int smbus_do_alert(struct device *dev, void *addrp) * The alert IRQ handler needs to hand work off to a task which can issue * SMBus calls, because those sleeping calls can't be made in IRQ context. */ -static void smbus_alert(struct work_struct *work) +static irqreturn_t smbus_alert(int irq, void *d) { - struct i2c_smbus_alert *alert; + struct i2c_smbus_alert *alert = d; struct i2c_client *ara; unsigned short prev_addr = 0; /* Not a valid address */ - alert = container_of(work, struct i2c_smbus_alert, alert); ara = alert->ara; for (;;) { @@ -115,21 +112,17 @@ static void smbus_alert(struct work_struct *work) prev_addr = data.addr; } - /* We handled all alerts; re-enable level-triggered IRQs */ - if (!alert->alert_edge_triggered) - enable_irq(alert->irq); + return IRQ_HANDLED; } -static irqreturn_t smbalert_irq(int irq, void *d) +static void smbalert_work(struct work_struct *work) { - struct i2c_smbus_alert *alert = d; + struct i2c_smbus_alert *alert; + + alert = container_of(work, struct i2c_smbus_alert, alert); - /* Disable level-triggered IRQs until we handle them */ - if (!alert->alert_edge_triggered) - disable_irq_nosync(irq); + smbus_alert(0, alert); - schedule_work(&alert->alert); - return IRQ_HANDLED; } /* Setup SMBALERT# infrastructure */ @@ -139,28 +132,28 @@ static int smbalert_probe(struct i2c_client *ara, struct i2c_smbus_alert_setup *setup = dev_get_platdata(&ara->dev); struct i2c_smbus_alert *alert; struct i2c_adapter *adapter = ara->adapter; - int res; + int res, irq; alert = devm_kzalloc(&ara->dev, sizeof(struct i2c_smbus_alert), GFP_KERNEL); if (!alert) return -ENOMEM; - alert->alert_edge_triggered = setup->alert_edge_triggered; - alert->irq = setup->irq; - INIT_WORK(&alert->alert, smbus_alert); + irq = setup->irq; + INIT_WORK(&alert->alert, smbalert_work); alert->ara = ara; - if (setup->irq > 0) { - res = devm_request_irq(&ara->dev, setup->irq, smbalert_irq, - 0, "smbus_alert", alert); + if (irq > 0) { + res = devm_request_threaded_irq(&ara->dev, irq, + NULL, smbus_alert, + IRQF_SHARED | IRQF_ONESHOT, + "smbus_alert", alert); if (res) return res; } i2c_set_clientdata(ara, alert); - dev_info(&adapter->dev, "supports SMBALERT#, %s trigger\n", - setup->alert_edge_triggered ? "edge" : "level"); + dev_info(&adapter->dev, "supports SMBALERT#\n"); return 0; } diff --git a/include/linux/i2c-smbus.h b/include/linux/i2c-smbus.h index a138502..19efbd1 100644 --- a/include/linux/i2c-smbus.h +++ b/include/linux/i2c-smbus.h @@ -42,7 +42,6 @@ * properly set. */ struct i2c_smbus_alert_setup { - unsigned int alert_edge_triggered:1; int irq; };