On 29.05.2019 18:00, Alex Marginean wrote:

On 5/29/2019 5:19 PM, Vladimir Oltean wrote:

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On 29.05.2019 15:27, Alex Marginean wrote:

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Hi Carlo, everyone,

I'm doing some MDIO work on a freescale/NXP platform and I bumped into errors with this command: => mdio r emdio#3 5 3 Reading from bus emdio#3 "Synchronous Abort" handler, esr 0x8600000e elr: ffffffff862b8000 lr : 000000008200cce4 (reloc) ...

mdio list does not list any PHYs currently because ethernet is using DM and the interfaces are not probed at this time. The PHY does exist on the bus though. The above scenario works with this commit reverted: e55047ec51a662c12ed53ff543ec7cdf158b2137 cmd: mdio: Switch to generic helpers when accessing the registers

The current code using generic helpers only works for PHYs that have been registered and show up in bus->phymap and crashes for arbitrary IDs. I find it useful to allow reading from other addresses over MDIO too, certainly helpful for people debugging MDIO on various boards.

What's your take on this? Could we revert the above patch, or should I add some code handling the case when bus->phymap comes up empty and then go to bus->read?

Thanks! Alex

Hi Alex,

Thanks for reporting this. I think that breaking access to arbitrary PHY addresses was only an unintentional side-effect here. Even moreso since having MDIO access to PHYs not defined in DT is desirable, and not only for debugging. It certainly seems easy to add it back by introducing something like the following (not tested):

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diff --git a/cmd/mdio.c b/cmd/mdio.c index efe8c9ef0954..5e219f699d8d 100644 --- a/cmd/mdio.c +++ b/cmd/mdio.c @@ -54,7 +54,10 @@ static int mdio_write_ranges(struct mii_dev *bus,

          for (devad = devadlo; devad <= devadhi; devad++) {
                  for (reg = reglo; reg <= reghi; reg++) {

•                        if (!extended)
  

•                        if (!phydev)
  

•                                err = bus->write(bus, addr, devad,
  

•                                                 reg, data);
  

•                        else if (!extended)
                                  err = phy_write_mmd(phydev, devad,
                                                      reg, data);
                          else
  

@@ -88,7 +91,9 @@ static int mdio_read_ranges(struct mii_dev *bus, for (reg = reglo; reg <= reghi; reg++) { int val;

•                        if (!extended)
  

•                        if (!phydev)
  

•                                val = bus->read(bus, addr, devad, reg);
  

•                        else if (!extended)
                                  val = phy_read_mmd(phydev, devad, reg);
                          else
                                  val = phydev->drv->readext(phydev, addr,
  

Of course in this case we're back to not having the indirect C45 convenience commands, but it's still much better than not having access at all.

If there are no objections I can volunteer to either test a patch or even submit one later today.

Regards, -Vladimir

Hey Vladimir,

The downside is that the original patch from Carlo replaced old API calls with the more generic API, and now we would switch to using both generic API and old API although this change doesn't actually add any functionality. It may be simpler to just switch to the old code, it's simpler than the three branches (!phydev, !extended and else) and it does the same thing.

Hi Alex,

I don't think that reverting is necessary. And in fact, the generic API does bring some functionality (albeit only for user convenience, but that matters sometimes too). Say a C22 PHY had a register at 7.1. To write a value it, previously you had to: mdio write <dev> 0xd 0x7 mdio write <dev> 0xe 0x1 mdio write <dev> 0xd 0x4007 mdio write <dev> 0xe <value> Now you can just: mdio write <dev> 7.1 <value>

Back to the change you suggested, I have the changes applied to my tree and it works: => mdio list emdio#3: => mdio r emdio#3 5 3 Reading from bus emdio#3 PHY at address 5: 3 - 0xd072

I can't test C45 right now on my set-up, I would expect it to work though.

Thanks! Alex

Thanks for testing, good to know that it works. I'll send a patch later today then.

-Vladimir