[lkml]   [2018]   [Apr]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH 0/3] USB: musb: dsps: phy fix and DT-topology support
Hi Johan,

On Fri, Apr 13, 2018 at 5:15 PM, Johan Hovold <> wrote:
> I've been carrying a patch out-of-tree since my work on improving the
> USB device-tree support which is needed to be able to describe USB
> topologies for musb based controllers.
> This patch, which associates the platform controller device with the
> glue device device-tree node, did not play well with the recent changes
> which added generic phy support to USB core however.
I'm the one who added this

> Like the recent dwc2 regression fixed by Arnd after the device-tree
> #phy-cell changes, the generic phy code in USB core can now also fail
> indefinitly with -EPROBE_DEFER when the controller uses a legacy USB
> phy.
> The second patch addresses this for musb, which handles its own (legacy
> and generic) phys, but something more may possibly now be needed for
> other platforms with legacy phys.
I'm not sure if I understand the problem yet - could you please
explain with your words what "legacy PHYs" are and how the "conflict"
with the PHY handling in USB core?

I am aware of two PHY subsystems:
- drivers/phy
-- also called "generic PHY framework"
-- uses a "phys" property
- drivers/usb/phy
-- also called "USB PHY framework"
-- AFAIK this should not be used for new drivers
-- uses an "usb-phy" property

the new PHY handling in USB core only parses the "phys" property and
thus should not conflict with "usb-phy" (the legacy property)

however, I probably missed something so I'd appreciate an explanation
how things can break

> In the process of debugging this, I stumbled over another issue which
> caused the dsps legacy phy init two be called twice on every probe and
> which is fixed by the first patch.
> Johan
> Johan Hovold (3):
> USB: musb: dsps: drop duplicate phy initialisation
> USB: musb: host: prevent core phy initialisation
> USB: musb: dsps: propagate device-tree node
> drivers/usb/musb/musb_dsps.c | 3 +--
> drivers/usb/musb/musb_host.c | 1 +
> 2 files changed, 2 insertions(+), 2 deletions(-)
> --
> 2.17.0


 \ /
  Last update: 2018-04-18 21:19    [W:0.093 / U:1.376 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site