Merge branch 'qca8k-improvements'

Ansuel Smith says:

====================
Multiple improvement to qca8k stability

Currently qca8337 switch are widely used on ipq8064 based router.
On these particular router it was notice a very unstable switch with
port not link detected as link with unknown speed, port dropping
randomly and general unreliability. Lots of testing and comparison
between this dsa driver and the original qsdk driver showed lack of some
additional delay and values. A main difference arised from the original
driver and the dsa one. The original driver didn't use MASTER regs to
read phy status and the dedicated mdio driver worked correctly. Now that
the dsa driver actually use these regs, it was found that these special
read/write operation required mutual exclusion to normal
qca8k_read/write operation. The add of mutex for these operation fixed
the random port dropping and now only the actual linked port randomly
dropped. Adding additional delay for set_page operation and fixing a bug
in the mdio dedicated driver fixed also this problem. The current driver
requires also more time to apply vlan switch. All of these changes and
tweak permit a now very stable and reliable dsa driver and 0 port
dropping. This series is currently tested by at least 5 user with
different routers and all reports positive results and no problems.

Changes v6:
- Fix spelling mistake
- Change ms to ns (confirmed by datasheet)
Changes v5:
- Removed mdio patch (sent separetly to try to reduce the series)
  I know it was asked to reduced this series since it big, but rework
  the new changes to skip and error check looks wrong. Since half of them
  are actually already reviewed I think it's better to keep this series as is.
- Improve rgmii configurable patch
- Move qca8k phy dedicated driver to at803x phy driver
- Add support for dedicated internal mdio driver for qca8k
Changes v4:
- Use iopoll for busy_wait function
- Better describe and split some confusing commits
- Fix bad rgmii delay configurable patch
- Drop phy generic patch to pass flags with phylink_connect_phy
- Add dsa2 patch to declare mdio node in the switch node
- Add dsa patch to permit dsa driver to declare custom get_phys_mii_mask
    Some background about the last 2 patch.
    The qca8k switch doesn't have a 1:1 map between port reg and phy reg.
    Currently it's used a function to convert port to the internal phy reg.
    I added some patch to fix this.
    - The dsa driver now check if the mdio node is present and use the of variant
      of the mdiobus_register
    - A custom phy_mii_mask is required as currently the mask is generated from
      the port reg, but in our case the mask would be different as it should be
      generated from the phy reg. To generalize this I added an extra function
      that driver can provide to pass custom phy_mii_mask.
Changes v3:
- Revert mdio writel changes (use regmap with REGCACHE disabled)
- Split propagate error patch to 4 different patch
Changes v2:
- Implemented phy driver for internal PHYs
  I'm testing cable test functions as I found some documentation that
  actually declare regs about it. Problem is that it doesn't actually
  work. It seems that the value set are ignored by the phy.
- Made the rgmii delay configurable
- Reordered patch
- Split mdio patches to more specific ones
- Reworked mdio driver to use readl/writel instead of regmap
- Reworked the entire driver to make it aware of any read/write error.
- Added phy generic patch to pass flags with phylink_connect_phy
  function
====================

Signed-off-by: David S. Miller <davem@davemloft.net>