Re: Ethernet controller not starting

[cc'ed netdev and davinci-linux-open-source]

--On March 03, 2014 19:39 -0500 Jon Ringle [off-list ref] wrote:

On Mon, Mar 3, 2014 at 6:43 PM, Rafael J. Wysocki [off-list ref]
wrote:

quoted

On Monday, March 03, 2014 02:41:01 PM Jon Ringle wrote:

quoted

I'm working on porting an ARM board from linux-3.10 to linux-3.12 (now
the latest LTS kernel).
I found that Ethernet controller on the board no longer comes up on
linux-3.12. I was able to bisect the issue I'm having to the following
commit:

quoted

  45f0a85c8258741d11bda25c0a5669c06267204a is the first bad commit
  commit 45f0a85c8258741d11bda25c0a5669c06267204a
  Author: Rafael J. Wysocki [off-list ref]
  Date:   Mon Jun 3 21:49:52 2013 +0200

      PM / Runtime: Rework the "runtime idle" helper routine

      The "runtime idle" helper routine, rpm_idle(), currently ignores
      return values from .runtime_idle() callbacks executed by it.
      However, it turns out that many subsystems use
      pm_generic_runtime_idle() which checks the return value of the
      driver's callback and executes pm_runtime_suspend() for the
      device unless that value is not 0.  If that logic is moved to
      rpm_idle() instead, pm_generic_runtime_idle() can be dropped
      and its users will not need any .runtime_idle() callbacks any
      more.

      Moreover, the PCI, SCSI, and SATA subsystems' .runtime_idle()
      routines, pci_pm_runtime_idle(), scsi_runtime_idle(), and
      ata_port_runtime_idle(), respectively, as well as a few drivers'
      ones may be simplified if rpm_idle() calls rpm_suspend() after
      0 has been returned by the .runtime_idle() callback executed by
      it.

      To reduce overall code bloat, make the changes described above.

      Tested-by: Mika Westerberg [off-list ref]
      Tested-by: Kevin Hilman [off-list ref]
      Signed-off-by: Rafael J. Wysocki [off-list ref]
      Acked-by: Kevin Hilman [off-list ref]
      Reviewed-by: Ulf Hansson [off-list ref]
      Acked-by: Alan Stern [off-list ref]

Can anyone offer any suggestions on what I should be looking for to
fix this on my board?

Any pointers to the driver in question?

drivers/net/ethernet/ti/davinci_emac.c

Hi Jon,
I have successfully used the davinci_emac driver on a custom board with an 
AM1808 SoC with Kernel 3.13 a few weeks ago. So at least 3.13 should work. 
Did you try more recent kernel versions than 3.12?

I also get the following output:

         Starting Network Manager Wait Online...
[   30.946509] davinci_mdio davinci_mdio.0: resetting idled controller
[   30.953220] net net0: attached PHY driver [Generic PHY]
(mii_bus:phy_addr=davinci_mdio-0:00, id=7c0f1)
[   30.962938] IPv6: ADDRCONF(NETDEV_UP): net0: link is not ready
[   31.082087] genirq: Flags mismatch irq 33. 00000000 (net0) vs.
00000000 (net0)

Is it correct that this warning can only appear in case of shared 
interrupts? See kernel/irq/manage.c. Since we don't use shared interrupts 
here: Are you sure your board configuration is correct with regard to emac 
interrupts? Is your configuration using device tree or not (my 
configuration is a none-devicetree one)? I also wonder why your network 
device is net0, on my board it's eth0, maybe this triggers some bug?

Christian