Thread (3 messages) 3 messages, 3 authors, 2014-05-16

Re: [PATCH] net: phy: Don't call phy_resume if phy_init_hw failed

From: Florian Fainelli <f.fainelli@gmail.com>
Date: 2014-05-14 20:22:34
Also in: lkml

2014-05-14 13:12 GMT-07:00 Guenter Roeck [off-list ref]:
After the call to phy_init_hw failed in phy_attach_direct, phy_detach is called
to detach the phy device from its network device. If the attached driver is a
generic phy driver, this also detaches the driver. Subsequently phy_resume
is called, which assumes without checking that a driver is attached to the
device. This will result in a crash such as

Unable to handle kernel paging request for data at address 0xffffffffffffff90
Faulting instruction address: 0xc0000000003a0e18
Oops: Kernel access of bad area, sig: 11 [#1]
...
NIP [c0000000003a0e18] .phy_attach_direct+0x68/0x17c
LR [c0000000003a0e6c] .phy_attach_direct+0xbc/0x17c
Call Trace:
[c0000003fc0475d0] [c0000000003a0e6c] .phy_attach_direct+0xbc/0x17c (unreliable)
[c0000003fc047670] [c0000000003a0ff8] .phy_connect_direct+0x28/0x98
[c0000003fc047700] [c0000000003f0074] .of_phy_connect+0x4c/0xa4

Only call phy_resume if phy_init_hw was successful.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>

Thanks!
quoted hunk ↗ jump to hunk
---
Another option might be to check in phy_detach if a driver is attached
to the device.

 drivers/net/phy/phy_device.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 0ce6066..4987a1c 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -614,8 +614,8 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev,
        err = phy_init_hw(phydev);
        if (err)
                phy_detach(phydev);
-
-       phy_resume(phydev);
+       else
+               phy_resume(phydev);

        return err;
 }
--
1.9.1


-- 
Florian
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