in case an HCD wants to use threaded irqs to spend
less time in hardirq context, we need
this. Eventually we will remove IRQF_ONESHOT but
only after all HCDs are fixed.
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
---
drivers/usb/core/hcd.c | 43 ++++++++++++++++++++++++++++++++++++++++---
include/linux/usb/hcd.h | 2 ++
2 files changed, 42 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 76a6cd0d3af9..66dc5a8dfca8 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -2420,7 +2420,8 @@ EXPORT_SYMBOL_GPL(usb_bus_start_enum);
* If the controller isn't HALTed, calls the driver's irq handler.
* Checks whether the controller is now dead.
*
- * Return: %IRQ_HANDLED if the IRQ was handled. %IRQ_NONE otherwise.
+ * Return: %IRQ_HANDLED if the IRQ was handled or %IRQ_WAKE_THREAD if we need to
+ * wake our threaded handler. %IRQ_NONE otherwise.
*/
irqreturn_t usb_hcd_irq (int irq, void *__hcd)
{
@@ -2433,6 +2434,29 @@ irqreturn_t usb_hcd_irq (int irq, void *__hcd)
}
EXPORT_SYMBOL_GPL(usb_hcd_irq);
+/**
+ * usb_hcd_threaded_irq - hook threaded IRQs to HCD framework (bus glue)
+ * @irq the IRQ for which a thread is being woken
+ * @__hcd: pointer to the HCD whose IRQ is being signaled
+ * If the controller isn't HALTed, calls the driver's irq handler.
+ * Checks whether the controller is now dead.
+ *
+ * Return: %IRQ_HANDLED if the IRQ was handled. %IRQ_NONE otherwise.
+ */
+irqreturn_t usb_hcd_threaded_irq (int irq, void *__hcd)
+{
+ struct usb_hcd *hcd = __hcd;
+
+ if (unlikely(HCD_DEAD(hcd) || !HCD_HW_ACCESSIBLE(hcd)))
+ return IRQ_NONE;
+
+ if (hcd->driver->threaded_irq)
+ return hcd->driver->threaded_irq(hcd);
+
+ return IRQ_NONE;
+}
+EXPORT_SYMBOL_GPL(usb_hcd_threaded_irq);
+
/*-------------------------------------------------------------------------*/
/**
@@ -2646,8 +2670,21 @@ static int usb_hcd_request_irqs(struct usb_hcd *hcd,
snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",
hcd->driver->description, hcd->self.busnum);
- retval = request_irq(irqnum, &usb_hcd_irq, irqflags,
- hcd->irq_descr, hcd);
+
+ /*
+ * NOTICE: we're assuming here that if an HCD implements
+ * threaded_irq, it's because it wants to use it. For now, we're
+ * leaving IRQF_ONESHOT in place, but soon enough we plan on
+ * removing that after all HCDs are fixed.
+ */
+ if (hcd->driver->threaded_irq)
+ retval = request_threaded_irq(irqnum, usb_hcd_irq,
+ usb_hcd_threaded_irq,
+ irqflags | IRQF_ONESHOT, hcd->irq_descr,
+ hcd);
+ else
+ retval = request_irq(irqnum, usb_hcd_irq, irqflags,
+ hcd->irq_descr, hcd);
if (retval != 0) {
dev_err(hcd->self.controller,
"request interrupt %d failed\n",
diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
index b98f831dcda3..75287dd91a52 100644
--- a/include/linux/usb/hcd.h
+++ b/include/linux/usb/hcd.h
@@ -242,6 +242,7 @@ struct hc_driver {
/* irq handler */
irqreturn_t (*irq) (struct usb_hcd *hcd);
+ irqreturn_t (*threaded_irq) (struct usb_hcd *hcd);
int flags;
#define HCD_MEMORY 0x0001 /* HC regs use memory (else I/O) */
@@ -479,6 +480,7 @@ void hcd_buffer_free(struct usb_bus *bus, size_t size,
/* generic bus glue, needed for host controllers that don't use PCI */
extern irqreturn_t usb_hcd_irq(int irq, void *__hcd);
+extern irqreturn_t usb_hcd_threaded_irq(int irq, void *__hcd);
extern void usb_hc_died(struct usb_hcd *hcd);
extern void usb_hcd_poll_rh_status(struct usb_hcd *hcd);
--
2.8.0.rc2
--
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