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Subject[PATCH RFC 0/5] Ethernet support for Zynq

I am trying to make Ethernet work on Zynq, whose Ethernet core is a
cadence macb.

I came across two issues: The first is, that Ethernet does not work on
the Zedboard platform, but on zc702 and zc706. In both cases the probing
looks good as far as I can tell:
[ 1.754502] libphy: MACB_mii_bus: probed
[ 2.775957] macb e000b000.ethernet eth0: Cadence GEM at 0xe000b000 irq 54 (00:0a:35:00:01:22)
[ 2.784638] macb e000b000.ethernet eth0: attached PHY driver [Marvell 88E1116R] (mii_bus:phy_addr=e000b000.etherne:07, irq=-1)
[ 1.755202] libphy: MACB_mii_bus: probed
[ 1.771422] macb e000b000.ethernet eth0: Cadence GEM at 0xe000b000 irq 54 (00:0a:35:00:01:22)
[ 1.780141] macb e000b000.ethernet eth0: attached PHY driver [Marvell 88E1510] (mii_bus:phy_addr=e000b000.etherne:00, irq=-1)

But on the Zed no actual connection can be established:
# udhcpc
udhcpc (v1.21.1) started
grep: /etc/resolv.conf: No such file or directory
Sending discover...
Sending discover...
[ 50.769745] macb e000b000.ethernet eth0: link up (1000/Full)
Sending discover...
Sending select for
Lease of obtained, lease time 600
deleting routers
route: SIOCDELRT: No such process
adding dns
adding dns
# ping
PING ( 56 data bytes
64 bytes from seq=0 ttl=64 time=0.848 ms
64 bytes from seq=1 ttl=64 time=0.350 ms

On Zed this just loops indefinitely printing "Sending discover...
The main difference is the different phy used on the Zed. Does
anybody have an idea what might go wrong here?

And my second issue is related to the macb clocks:
Currently the macb driver expects two input clocks - pclk and hclk. At
the same time the actual Ethernet clock - tx_clk - is not handled in the
driver at all.
On Zynq's implementation of the macb, pclk and hclk are the same clock
and we provide a tx_clk separately and the driver needs to adjust it
according to the negotiated link speed (at least in some/most use-cases).
Handling this is sketched out in 5/5. But it does not really look nice.
- How do other SOCs handle tx_clk adjustments?
- the bindings do not really fit Zynq's implementation. How can we
ensure that clocks are mandatory or optional as required by the SOC
this core is implemented in?

The first four patches in this series are probably good to go.


Soren Brinkmann (5):
net: macb: Migrate to dev_pm_ops
net: macb: Migrate to devm clock interface
net: macb: Use devm_ioremap()
net: macb: Use devm_request_irq()
net: macb: Adjust tx_clk when link speed changes

drivers/net/ethernet/cadence/macb.c | 128 ++++++++++++++++++++++++++++--------
drivers/net/ethernet/cadence/macb.h | 1 +
2 files changed, 100 insertions(+), 29 deletions(-)


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