[PATCH RFC 2/6] net: phy: Use threaded IRQ, to allow IRQ from sleeping devices

The interrupt lines from PHYs maybe connected to I2C bus expanders, or
from switches on MDIO busses. Such interrupts are sourced from devices
which sleep, so use threaded interrupts. Threaded interrupts require
that the interrupt requester also uses the threaded API. Change the
phylib to use the threaded API, which is backwards compatible with
none-threaded IRQs.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
---
 drivers/net/phy/phy.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index c6f66832a1a6..5c29ed72f721 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c

@@ -722,10 +722,9 @@ phy_err:
 int phy_start_interrupts(struct phy_device *phydev)
 {
 	atomic_set(&phydev->irq_disable, 0);
-	if (request_irq(phydev->irq, phy_interrupt,
-				IRQF_SHARED,
-				"phy_interrupt",
-				phydev) < 0) {
+	if (request_threaded_irq(phydev->irq, NULL, phy_interrupt,
+				 IRQF_ONESHOT, "phy_interrupt",
+				 phydev) < 0) {
 		pr_warn("%s: Can't get IRQ %d (PHY)\n",
 			phydev->mdio.bus->name, phydev->irq);
 		phydev->irq = PHY_POLL;

-- 
2.9.3

Hello.

On 9/28/2016 11:32 AM, Andrew Lunn wrote:

   What about IRQF_SHARED?

MBR, Sergei

On Wed, Sep 28, 2016 at 02:38:03PM +0300, Sergei Shtylyov wrote:

Hello.

On 9/28/2016 11:32 AM, Andrew Lunn wrote:

quoted

The interrupt lines from PHYs maybe connected to I2C bus expanders, or
from switches on MDIO busses. Such interrupts are sourced from devices
which sleep, so use threaded interrupts. Threaded interrupts require
that the interrupt requester also uses the threaded API. Change the
phylib to use the threaded API, which is backwards compatible with
none-threaded IRQs.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
---
drivers/net/phy/phy.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index c6f66832a1a6..5c29ed72f721 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c

@@ -722,10 +722,9 @@ phy_err:

int phy_start_interrupts(struct phy_device *phydev)
{
	atomic_set(&phydev->irq_disable, 0);
-	if (request_irq(phydev->irq, phy_interrupt,
-				IRQF_SHARED,
-				"phy_interrupt",
-				phydev) < 0) {
+	if (request_threaded_irq(phydev->irq, NULL, phy_interrupt,
+				 IRQF_ONESHOT, "phy_interrupt",

   What about IRQF_SHARED?

I will check if you can have a shared oneshot.

  Andrew

On Wed, Sep 28, 2016 at 02:38:03PM +0300, Sergei Shtylyov wrote:

Hello.

On 9/28/2016 11:32 AM, Andrew Lunn wrote:

quoted

The interrupt lines from PHYs maybe connected to I2C bus expanders, or
from switches on MDIO busses. Such interrupts are sourced from devices
which sleep, so use threaded interrupts. Threaded interrupts require
that the interrupt requester also uses the threaded API. Change the
phylib to use the threaded API, which is backwards compatible with
none-threaded IRQs.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
---
drivers/net/phy/phy.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index c6f66832a1a6..5c29ed72f721 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c

@@ -722,10 +722,9 @@ phy_err:

int phy_start_interrupts(struct phy_device *phydev)
{
	atomic_set(&phydev->irq_disable, 0);
-	if (request_irq(phydev->irq, phy_interrupt,
-				IRQF_SHARED,
-				"phy_interrupt",
-				phydev) < 0) {
+	if (request_threaded_irq(phydev->irq, NULL, phy_interrupt,
+				 IRQF_ONESHOT, "phy_interrupt",

   What about IRQF_SHARED?

IRQF_ONESHOT | IRQF_SHARED does work.

However, it requires all uses of the interrupt use the same flags.
The commit messages suggests IRQF_SHARED is there because of boards
which have multiple PHYs using one IRQ. That case will work, since all
PHYs will be using this code.

What will be an issue is if the sharing is between a PHY and something
else. That something else will also need to use IRQF_ONESHOT.  Anybody
know if this situation actually exists?

Thanks
     Andrew