[PATCH 3.16 056/233] usb: host: xhci: simplify irq handler return

From: Ben Hutchings
Date: Sat Sep 09 2017 - 19:01:20 EST


3.16.48-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>

commit 76a35293b901915c5dcb4a87a4a0da8d7caf39fe upstream.

Instead of having several return points, let's use a local variable and
a single place to return. This makes the code slightly easier to read.

[set ret = IRQ_HANDLED in default working case -Mathias]
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/usb/host/xhci-ring.c | 32 +++++++++++++++++---------------
1 file changed, 17 insertions(+), 15 deletions(-)

--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -2688,27 +2688,28 @@ static int xhci_handle_event(struct xhci
irqreturn_t xhci_irq(struct usb_hcd *hcd)
{
struct xhci_hcd *xhci = hcd_to_xhci(hcd);
- u32 status;
- u64 temp_64;
union xhci_trb *event_ring_deq;
+ irqreturn_t ret = IRQ_NONE;
dma_addr_t deq;
+ u64 temp_64;
+ u32 status;

spin_lock(&xhci->lock);
/* Check if the xHC generated the interrupt, or the irq is shared */
status = readl(&xhci->op_regs->status);
- if (status == 0xffffffff)
- goto hw_died;
-
- if (!(status & STS_EINT)) {
- spin_unlock(&xhci->lock);
- return IRQ_NONE;
+ if (status == 0xffffffff) {
+ ret = IRQ_HANDLED;
+ goto out;
}
+
+ if (!(status & STS_EINT))
+ goto out;
+
if (status & STS_FATAL) {
xhci_warn(xhci, "WARNING: Host System Error\n");
xhci_halt(xhci);
-hw_died:
- spin_unlock(&xhci->lock);
- return IRQ_HANDLED;
+ ret = IRQ_HANDLED;
+ goto out;
}

/*
@@ -2738,9 +2739,8 @@ hw_died:
temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
xhci_write_64(xhci, temp_64 | ERST_EHB,
&xhci->ir_set->erst_dequeue);
- spin_unlock(&xhci->lock);
-
- return IRQ_HANDLED;
+ ret = IRQ_HANDLED;
+ goto out;
}

event_ring_deq = xhci->event_ring->dequeue;
@@ -2765,10 +2765,12 @@ hw_died:
/* Clear the event handler busy flag (RW1C); event ring is empty. */
temp_64 |= ERST_EHB;
xhci_write_64(xhci, temp_64, &xhci->ir_set->erst_dequeue);
+ ret = IRQ_HANDLED;

+out:
spin_unlock(&xhci->lock);

- return IRQ_HANDLED;
+ return ret;
}

irqreturn_t xhci_msi_irq(int irq, void *hcd)