Device like igb gets runtime suspended when there's no link partner. We
can't get correct speed under that state:
$ cat /sys/class/net/enp3s0/speed
1000
In addition to that, an error can also be spotted in dmesg:
[ 385.991957] igb 0000:03:00.0 enp3s0: PCIe link lost
Since device can only be runtime suspended when there's no link partner,
we can directly report the speed and duplex as unknown.
Cc: Jeff Kirsher <[email protected]>
Cc: Aaron Brown <[email protected]>
Suggested-by: Alexander Duyck <[email protected]>
Signed-off-by: Kai-Heng Feng <[email protected]>
---
net/ethtool/ioctl.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index 10d929abdf6a..2ba04aa9d775 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -28,6 +28,7 @@
#include <net/xdp_sock.h>
#include <net/flow_offload.h>
#include <linux/ethtool_netlink.h>
+#include <linux/pm_runtime.h>
#include "common.h"
@@ -429,6 +430,13 @@ int __ethtool_get_link_ksettings(struct net_device *dev,
return -EOPNOTSUPP;
memset(link_ksettings, 0, sizeof(*link_ksettings));
+
+ if (pm_runtime_suspended(dev->dev.parent)) {
+ link_ksettings->base.duplex = DUPLEX_UNKNOWN;
+ link_ksettings->base.speed = SPEED_UNKNOWN;
+ return 0;
+ }
+
return dev->ethtool_ops->get_link_ksettings(dev, link_ksettings);
}
EXPORT_SYMBOL(__ethtool_get_link_ksettings);
--
2.17.1
On 3/26/2020 7:45 PM, Kai-Heng Feng wrote:
> Device like igb gets runtime suspended when there's no link partner. We
> can't get correct speed under that state:
> $ cat /sys/class/net/enp3s0/speed
> 1000
>
> In addition to that, an error can also be spotted in dmesg:
> [ 385.991957] igb 0000:03:00.0 enp3s0: PCIe link lost
>
> Since device can only be runtime suspended when there's no link partner,
> we can directly report the speed and duplex as unknown.
>
> Cc: Jeff Kirsher <[email protected]>
> Cc: Aaron Brown <[email protected]>
> Suggested-by: Alexander Duyck <[email protected]>
> Signed-off-by: Kai-Heng Feng <[email protected]>
I would push this to the responsibility of the various drivers instead
of making this part of the standard ethtool implementation.
--
Florian
> On Mar 27, 2020, at 10:56, Florian Fainelli <[email protected]> wrote:
>
>
>
> On 3/26/2020 7:45 PM, Kai-Heng Feng wrote:
>> Device like igb gets runtime suspended when there's no link partner. We
>> can't get correct speed under that state:
>> $ cat /sys/class/net/enp3s0/speed
>> 1000
>>
>> In addition to that, an error can also be spotted in dmesg:
>> [ 385.991957] igb 0000:03:00.0 enp3s0: PCIe link lost
>>
>> Since device can only be runtime suspended when there's no link partner,
>> we can directly report the speed and duplex as unknown.
>>
>> Cc: Jeff Kirsher <[email protected]>
>> Cc: Aaron Brown <[email protected]>
>> Suggested-by: Alexander Duyck <[email protected]>
>> Signed-off-by: Kai-Heng Feng <[email protected]>
>
> I would push this to the responsibility of the various drivers instead
> of making this part of the standard ethtool implementation.
My original approach [1] is to ask device to runtime resume before calling __ethtool_get_link_ksettings().
Unfortunately it will cause a deadlock if the runtime resume routine wants to hold rtnl_lock.
However, it should be totally fine (and sometimes necessary) to be able to hold rtnl_lock in runtime resume routine as Alexander explained [2].
As suggested, this patch handles the situation directly in __ethtool_get_link_ksettings().
[1] https://lore.kernel.org/lkml/[email protected]/
[2] https://lkml.org/lkml/2020/3/26/989
Kai-Heng
> --
> Florian