Messages in this thread Patch in this message | | | From | Chris Packham <> | Subject | [PATCH v2 2/2] uio: use threaded interrupts | Date | Tue, 9 Apr 2024 11:40:49 +1200 |
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Split the existing uio_interrupt into a hardirq handler and a thread function. The hardirq handler deals with the interrupt source in hardware, the thread function notifies userspace that there is an event to be handled.
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz> ---
Notes: I find myself needing to have a UIO interrupt associated with an interrupt pin on a PCA9539 (yes I know, it's a terrible chip but HW engineers love it because it's cheap). Prior to this the UIO registration fails with: [ 6.484699] uio_pdrv_genirq detect-gpio-9: unable to register uio device [ 6.484722] uio_pdrv_genirq detect-gpio-9: probe with driver uio_pdrv_genirq failed with error -22 The -EINVAL ultimately comes from __setup_irq() where it knows the interrupt descriptor is nested but we haven't provided a thread_fn. Changes in v2: - None
drivers/uio/uio.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-)
diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c index bb77de6fa067..a86cf2e4f200 100644 --- a/drivers/uio/uio.c +++ b/drivers/uio/uio.c @@ -442,18 +442,27 @@ EXPORT_SYMBOL_GPL(uio_event_notify); * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer * @dev_id: Pointer to the devices uio_device structure */ -static irqreturn_t uio_interrupt(int irq, void *dev_id) +static irqreturn_t uio_interrupt_handler(int irq, void *dev_id) { struct uio_device *idev = (struct uio_device *)dev_id; irqreturn_t ret; ret = idev->info->handler(irq, idev->info); if (ret == IRQ_HANDLED) - uio_event_notify(idev->info); + ret = IRQ_WAKE_THREAD; return ret; } +static irqreturn_t uio_interrupt_thread(int irq, void *dev_id) +{ + struct uio_device *idev = (struct uio_device *)dev_id; + + uio_event_notify(idev->info); + + return IRQ_HANDLED; +} + struct uio_listener { struct uio_device *dev; s32 event_count; @@ -1024,8 +1033,8 @@ int __uio_register_device(struct module *owner, * FDs at the time of unregister and therefore may not be * freed until they are released. */ - ret = request_irq(info->irq, uio_interrupt, - info->irq_flags, info->name, idev); + ret = request_threaded_irq(info->irq, uio_interrupt_handler, uio_interrupt_thread, + info->irq_flags, info->name, idev); if (ret) { info->uio_dev = NULL; goto err_request_irq; -- 2.43.2
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