Re: [PATCH] net: phy: Move interrupt check from phy_check to phy_interrupt

On Thu, Mar 08, 2018 at 05:29:05PM +0100, Andrew Lunn wrote:

On Wed, Mar 07, 2018 at 04:50:42PM -0600, Brad Mouring wrote:

quoted

If multiple phys share the same interrupt (e.g. a multi-phy chip),
the first device registered is the only one checked as phy_interrupt
will always return IRQ_HANDLED if the first phydev is not halted.
Move the interrupt check into phy_interrupt and, if it was not this
phydev, return IRQ_NONE to allow other devices on this irq a chance
to check if it was their interrupt.

Signed-off-by: Brad Mouring <redacted>
---
 drivers/net/phy/phy.c | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index e3e29c2b028b..ff1aa815568f 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c

@@ -632,6 +632,12 @@ static irqreturn_t phy_interrupt(int irq, void *phy_dat)
 	if (PHY_HALTED == phydev->state)
 		return IRQ_NONE;		/* It can't be ours.  */
 
+	if (phy_interrupt_is_valid(phydev)) {

Hi Brad

Is this check needed? Can phy_interrupt() be called for a PHY which
does not have an interrupt?

Ah, fair point (and I guess a result of copy-pasting without
thinking), to address this and the next point...

quoted

+		if (phydev->drv->did_interrupt &&
+			!phydev->drv->did_interrupt(phydev))
+			return IRQ_NONE;
+	}
+
 	phy_change(phydev);
 
 	return IRQ_HANDLED;

@@ -725,16 +731,6 @@ EXPORT_SYMBOL(phy_stop_interrupts);
  */
 void phy_change(struct phy_device *phydev)
 {
-	if (phy_interrupt_is_valid(phydev)) {
-		if (phydev->drv->did_interrupt &&
-		    !phydev->drv->did_interrupt(phydev))
-			return;
-
-		if (phydev->state == PHY_HALTED)
-			if (phy_disable_interrupts(phydev))
-				goto phy_err;
-	}
-

phy_change() can also be called via phy_mac_interrupt(). I wonder if
this change is going to break anything? Did you think about that?

Thanks for pointing this out. I'll post a v2 that (hopefully) address
both of these valid points.

Thanks,
Brad