Thanks for the quick reply.
On 2020-01-09 4:02 a.m., Felipe Balbi wrote:
Hi,
Jonathan Thibault <jonathan@xxxxxxxxxxx> writes:
Greetings,
I am currently trying to port OpenWRT to Ubiquiti's EdgeRouter 4 which
is a Cavium Octeon 7130. While investigating to support XHCI (the
device has a single USB3 port), I ran into the dwc3 driver which
apparently supports that very chipset via the dwc3-of-simple glue.
Looking at Ubiquiti's own firmware, it seems they are using a modified
version of the standard xhci-platform driver.
So now I am faced with two different approaches:
1- Attempt to replicate Ubiquiti's modifications to xhci-plat.
2- Switch to dwc3-of-simple.
With option 1, so far, I can get xhci to load by merely adding a
'.compatible =' member to usb_xhci_of_match[], but the driver complains
about LPM algorithms and disables LPM (which may be fine, I don't know
if it is even supported on this device).
Option 2 (where you might hopefully help), potentially involves more
modification to the OpenWRT since their Octeon kernel config does not
appear to enable CONFIG_COMMON_CLK, which the driver depends on. And I
do not know if I should also disable standard ohci and ehci drivers once
I manage to enable the USB_DWC3_OF_SIMPLE.
I'm looking for recommendations on the best approach. Keep in mind that
while I can cobble together some ugly but functional hacks, I am not an
experienced kernel dev.
Just switch to dwc3-of-simple, it already supports the SoC you're
dealing with. Try removing the dependency on CONFIG_COMMON_CLK. I think
we already get empty stubs when common clk is disabled.
If that works for you, that's an easy patch.
Sadly, while it does build without the COMMON_CLK dependency, probing fails:
[ 4.881646] dwc3 1680000000000.xhci: Configuration mismatch. dr_mode
forced to host
[ 4.889574] dwc3 1690000000000.xhci: Configuration mismatch. dr_mode
forced to host
[ 4.897546] dwc3-of-simple: probe of 1180068000000.uctl failed with
error -12
[ 4.904715] dwc3-of-simple: probe of 1180069000000.uctl failed with
error -12
The return value suggests that it's from the if(!simple->clks) check in
dwc3_of_simple_clk_init().
The configuration mismatch warning is a bit of a mystery to me as well
since the only mode available in kernel config is USB_DWC3_HOST and what
I selected. Would this be because the controller itself is reporting
another configuration?
--
Jonathan Thibault
Analyste/Administrateur Réseau
Navigue
97, route 132, Saint-Godefroi (Québec) G0C 3C0
581-357-2015
jonathan@xxxxxxxxxxx
www.navigue.com
