From mboxrd@z Thu Jan 1 00:00:00 1970 From: Phil Reid Subject: [PATCH v5 1/9] i2c: i2c-smbus: Support threaded irqs. Date: Mon, 1 May 2017 16:49:51 +0800 Message-ID: <1493628599-30552-2-git-send-email-preid@electromag.com.au> References: <1493628599-30552-1-git-send-email-preid@electromag.com.au> Return-path: In-Reply-To: <1493628599-30552-1-git-send-email-preid@electromag.com.au> Sender: linux-i2c-owner@vger.kernel.org To: wsa@the-dreams.de, robh+dt@kernel.org, mark.rutland@arm.com, sre@kernel.org, peda@axentia.se, preid@electromag.com.au, linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, linux-pm@vger.kernel.org List-Id: devicetree@vger.kernel.org handle_nested_irq calls the threaded irq handler. So if the smbus_alert irq is being generated via this an null address is dereferenced. Split irq up into separate functions to allow thread / non thread irq to work correctly. Signed-off-by: Phil Reid --- drivers/i2c/i2c-smbus.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c index f9271c7..b272493 100644 --- a/drivers/i2c/i2c-smbus.c +++ b/drivers/i2c/i2c-smbus.c @@ -72,13 +72,12 @@ 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 (;;) { @@ -115,6 +114,17 @@ static void smbus_alert(struct work_struct *work) prev_addr = data.addr; } + return IRQ_HANDLED; +} + +static void smbalert_work(struct work_struct *work) +{ + struct i2c_smbus_alert *alert; + + alert = container_of(work, struct i2c_smbus_alert, alert); + + smbus_alert(alert->irq, alert); + /* We handled all alerts; re-enable level-triggered IRQs */ if (!alert->alert_edge_triggered) enable_irq(alert->irq); @@ -148,12 +158,14 @@ static int smbalert_probe(struct i2c_client *ara, alert->alert_edge_triggered = setup->alert_edge_triggered; alert->irq = setup->irq; - INIT_WORK(&alert->alert, smbus_alert); + 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); + res = devm_request_threaded_irq(&ara->dev, alert->irq, + smbalert_irq, smbus_alert, + IRQF_SHARED | IRQF_ONESHOT, + "smbus_alert", alert); if (res) return res; } -- 1.8.3.1