[PATCH 4.4 40/73] Revert "phy: IRQ cannot be shared"

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

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

From: Xander Huff <xander.huff@xxxxxx>


[ Upstream commit c3e70edd7c2eed6acd234627a6007627f5c76e8e ]

This reverts:
  commit 33c133cc7598 ("phy: IRQ cannot be shared")

On hardware with multiple PHY devices hooked up to the same IRQ line, allow
them to share it.

Sergei Shtylyov says:
  "I'm not sure now what was the reason I concluded that the IRQ sharing
  was impossible... most probably I thought that the kernel IRQ handling
  code exited the loop over the IRQ actions once IRQ_HANDLED was returned
  -- which is obviously not so in reality..."

Signed-off-by: Xander Huff <xander.huff@xxxxxx>
Signed-off-by: Nathan Sullivan <nathan.sullivan@xxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/phy/phy.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -640,8 +640,10 @@ phy_err:
 int phy_start_interrupts(struct phy_device *phydev)
 {
 	atomic_set(&phydev->irq_disable, 0);
-	if (request_irq(phydev->irq, phy_interrupt, 0, "phy_interrupt",
-			phydev) < 0) {
+	if (request_irq(phydev->irq, phy_interrupt,
+				IRQF_SHARED,
+				"phy_interrupt",
+				phydev) < 0) {
 		pr_warn("%s: Can't get IRQ %d (PHY)\n",
 			phydev->bus->name, phydev->irq);
 		phydev->irq = PHY_POLL;