[1/2] net: smsc911x: Fix bug where PHY interrupts are overwritten by 0
diff mbox

Message ID 1466092470-20958-1-git-send-email-jeremy.linton@arm.com
State Changes Requested, archived
Delegated to: David Miller
Headers show

Commit Message

Jeremy Linton June 16, 2016, 3:54 p.m. UTC
By default, mdiobus_alloc() sets the PHY's to polling mode, but a
pointer size memcpy means that couple IRQs (depending
on 32-bit or 64-bit kernels) end up being overwritten with
a value of 0. This means that PHY_POLL is disabled and results
in unpredictable behavior depending on the PHYs location on the mdio
bus. Remove that memcpy and the now unused phy_irq member to force
SMSC911x PHY's into polling mode 100% of the time.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
---
 drivers/net/ethernet/smsc/smsc911x.c | 2 --
 1 file changed, 2 deletions(-)

Comments

Andrew Lunn June 16, 2016, 4:33 p.m. UTC | #1
On Thu, Jun 16, 2016 at 10:54:30AM -0500, Jeremy Linton wrote:
> By default, mdiobus_alloc() sets the PHY's to polling mode, but a
> pointer size memcpy means that couple IRQs (depending
> on 32-bit or 64-bit kernels) end up being overwritten with
> a value of 0. This means that PHY_POLL is disabled and results
> in unpredictable behavior depending on the PHYs location on the mdio
> bus. Remove that memcpy and the now unused phy_irq member to force
> SMSC911x PHY's into polling mode 100% of the time.
> 
> Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew
Sergei Shtylyov June 16, 2016, 6:55 p.m. UTC | #2
On 06/16/2016 06:54 PM, Jeremy Linton wrote:

> By default, mdiobus_alloc() sets the PHY's to polling mode, but a

    Rather "PHYs".

> pointer size memcpy means that couple IRQs (depending

    Could be more words on this line, it's broken too early, I think.

> on 32-bit or 64-bit kernels) end up being overwritten with
> a value of 0. This means that PHY_POLL is disabled and results
> in unpredictable behavior depending on the PHYs location on the mdio

    Contrariwise, "PHY's" here. And it's MDIO.

> bus. Remove that memcpy and the now unused phy_irq member to force
> SMSC911x PHY's into polling mode 100% of the time.
>
> Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>

Acked-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>

[...]

MBR, Sergei
Sergei Shtylyov June 16, 2016, 7:53 p.m. UTC | #3
On 06/16/2016 09:55 PM, Sergei Shtylyov wrote:

>> By default, mdiobus_alloc() sets the PHY's to polling mode, but a
>
>    Rather "PHYs".
>
>> pointer size memcpy means that couple IRQs (depending
>
>    Could be more words on this line, it's broken too early, I think.
>
>> on 32-bit or 64-bit kernels) end up being overwritten with
>> a value of 0. This means that PHY_POLL is disabled and results
>> in unpredictable behavior depending on the PHYs location on the mdio
>
>    Contrariwise, "PHY's" here. And it's MDIO.
>
>> bus. Remove that memcpy and the now unused phy_irq member to force
>> SMSC911x PHY's into polling mode 100% of the time.
>>
>> Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
>
> Acked-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>

    I was going to add the following too but just forgot:

Fixes: e7f4dc3536a4 ("mdio: Move allocation of interrupts into core")

> [...]

MBR, Sergei

Patch
diff mbox

diff --git a/drivers/net/ethernet/smsc/smsc911x.c b/drivers/net/ethernet/smsc/smsc911x.c
index 8af2556..b5ab5e1 100644
--- a/drivers/net/ethernet/smsc/smsc911x.c
+++ b/drivers/net/ethernet/smsc/smsc911x.c
@@ -116,7 +116,6 @@  struct smsc911x_data {
 
 	struct phy_device *phy_dev;
 	struct mii_bus *mii_bus;
-	int phy_irq[PHY_MAX_ADDR];
 	unsigned int using_extphy;
 	int last_duplex;
 	int last_carrier;
@@ -1073,7 +1072,6 @@  static int smsc911x_mii_init(struct platform_device *pdev,
 	pdata->mii_bus->priv = pdata;
 	pdata->mii_bus->read = smsc911x_mii_read;
 	pdata->mii_bus->write = smsc911x_mii_write;
-	memcpy(pdata->mii_bus->irq, pdata->phy_irq, sizeof(pdata->mii_bus));
 
 	pdata->mii_bus->parent = &pdev->dev;