When suspending/resuming an interface which was not up, we saw mdiobus
related PM handling despite 'mac_managed_pm' being set for RAVB/SH_ETH.
Heiner kindly suggested the fix to set this flag at probe time, not at
init/open time. I implemented his suggestion and it works fine on these
two Renesas drivers. These are patches 1+2.

I then looked which other drivers could be affected by the same problem.
I could only identify two where I am quite sure. Because I don't have
any HW, I opted to at least add a FIXME and send this out as patches
3+4. Ideally, they will never need to go upstream because the relevant
people will see their patch and do something like I did for patches 1+2.

Looking forward to comments. Thanks and happy hacking!


Wolfram Sang (4):
  ravb: avoid PHY being resumed when interface is not up
  sh_eth: avoid PHY being resumed when interface is not up
  fec: add FIXME to move 'mac_managed_pm' to probe
  smsc911x: add FIXME to move 'mac_managed_pm' to probe

 drivers/net/ethernet/freescale/fec_main.c |  1 +
 drivers/net/ethernet/renesas/ravb_main.c  | 12 ++++++++++--
 drivers/net/ethernet/renesas/sh_eth.c     | 12 ++++++++++--
 drivers/net/ethernet/smsc/smsc911x.c      |  1 +
 4 files changed, 22 insertions(+), 4 deletions(-)

-- 
2.30.2

On Tue, Mar 14, 2023 at 02:14:38PM +0100, Wolfram Sang wrote:
> When suspending/resuming an interface which was not up, we saw mdiobus
> related PM handling despite 'mac_managed_pm' being set for RAVB/SH_ETH.
> Heiner kindly suggested the fix to set this flag at probe time, not at
> init/open time. I implemented his suggestion and it works fine on these
> two Renesas drivers. These are patches 1+2.
> 
> I then looked which other drivers could be affected by the same problem.
> I could only identify two where I am quite sure. Because I don't have
> any HW, I opted to at least add a FIXME and send this out as patches
> 3+4. Ideally, they will never need to go upstream because the relevant
> people will see their patch and do something like I did for patches 1+2.
> 
> Looking forward to comments. Thanks and happy hacking!

Hi Wolfram,

an initial comment is, and I know this is a bit of a pain,
that 'net' and 'net-next' patches need to be split into separate serries.

And if there are dependencies, the 'net' series should go first, and then
the 'net-next' series should go out once the 'net' patches have been
accepted and 'net' has been merged into 'net-next', which I believe occurs
after Linus has pulled the weekly 'net' pull request, which typically
occurs on Thursdays.

> Wolfram Sang (4):
>   ravb: avoid PHY being resumed when interface is not up
>   sh_eth: avoid PHY being resumed when interface is not up
>   fec: add FIXME to move 'mac_managed_pm' to probe
>   smsc911x: add FIXME to move 'mac_managed_pm' to probe
> 
>  drivers/net/ethernet/freescale/fec_main.c |  1 +
>  drivers/net/ethernet/renesas/ravb_main.c  | 12 ++++++++++--
>  drivers/net/ethernet/renesas/sh_eth.c     | 12 ++++++++++--
>  drivers/net/ethernet/smsc/smsc911x.c      |  1 +
>  4 files changed, 22 insertions(+), 4 deletions(-)
> 
> -- 
> 2.30.2
>

Hi Simon!

> an initial comment is, and I know this is a bit of a pain,
> that 'net' and 'net-next' patches need to be split into separate serries.

Thanks for the heads up. I will refactor the series. First a part which
shall go into "net" and I will make the second part RFC with more
explanations how to reproduce the issue.

All the best,

   Wolfram

On Tue, Mar 14, 2023 at 02:14:38PM +0100, Wolfram Sang wrote:
> When suspending/resuming an interface which was not up, we saw mdiobus
> related PM handling despite 'mac_managed_pm' being set for RAVB/SH_ETH.
> Heiner kindly suggested the fix to set this flag at probe time, not at
> init/open time. I implemented his suggestion and it works fine on these
> two Renesas drivers. These are patches 1+2.
> 
> I then looked which other drivers could be affected by the same problem.
> I could only identify two where I am quite sure. Because I don't have
> any HW, I opted to at least add a FIXME and send this out as patches
> 3+4. Ideally, they will never need to go upstream because the relevant
> people will see their patch and do something like I did for patches 1+2.
> 
> Looking forward to comments. Thanks and happy hacking!
> 
> 
> Wolfram Sang (4):
>   ravb: avoid PHY being resumed when interface is not up
>   sh_eth: avoid PHY being resumed when interface is not up
>   fec: add FIXME to move 'mac_managed_pm' to probe
>   smsc911x: add FIXME to move 'mac_managed_pm' to probe
> 
>  drivers/net/ethernet/freescale/fec_main.c |  1 +
>  drivers/net/ethernet/renesas/ravb_main.c  | 12 ++++++++++--
>  drivers/net/ethernet/renesas/sh_eth.c     | 12 ++++++++++--
>  drivers/net/ethernet/smsc/smsc911x.c      |  1 +
>  4 files changed, 22 insertions(+), 4 deletions(-)
> 
> -- 
> 2.30.2
> 

Unfortunately, I wasn't able to check the series in terms of content, but
I have no objections to the logic and coding style.

For the series.
Reviewed-by: Michal Kubiak <michal.kubiak@intel.com>

Thanks,
Michal