Re: [PATCH v4] usb: dwc3: Don't switch OTG -> peripheral if extcon is present

[Andrey Smirnov]

On Fri, Sep 23, 2022 at 11:58 AM Andy Shevchenko
<andriy.shevchenko@xxxxxxxxx> wrote:
>
> +Stephen to help to realize what the mess we have now...
>
> On Fri, Sep 23, 2022 at 08:35:13PM +0200, Sven Peter wrote:
> > On Fri, Sep 23, 2022, at 20:23, Andrey Smirnov wrote:
> > > On Fri, Sep 23, 2022 at 9:42 AM Andy Shevchenko
> > > <andriy.shevchenko@xxxxxxxxx> wrote:
> > >>
> > >> On Thu, Sep 22, 2022 at 04:32:55PM -0700, Andrey Smirnov wrote:
> > >> > On Thu, Sep 22, 2022 at 3:23 AM Ferry Toth <fntoth@xxxxxxxxx> wrote:
> > >> > > On 22-09-2022 12:08, Andy Shevchenko wrote:
> > >> > > On Sun, Apr 03, 2022 at 09:49:07AM -0700, Andrey Smirnov wrote:
> > >>
> > >> FYI: For now I sent a revert, but if we got a solution quicker we always
> > >> can choose the course of actions.
> > >>
> > >
> > > I think we have another problem. This patch happened in parallel to mine
> > >
> > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v6.0-rc6&id=ab7aa2866d295438dc60522f85c5421c6b4f1507
> > >
> > > so my changes didn't have that fix in mind and I think your revert
> > > will not preserve that fix. Can you update your revert to take care of
> > > that too, please?
> > >
> > > I'm really confused how the above commit could be followed up by:
> > >
> > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/usb/dwc3/drd.c?h=v6.0-rc6&id=0f01017191384e3962fa31520a9fd9846c3d352f
> > >
> > > the diffs in dwc3_drd_init seem contradictory
> >
> > I noticed this a while ago when I finally rebased the M1 USB3 PHY WIP branch
> > and have been meaning to send a fix. Then life unfortunately got in the way and
> > I completely forgot about it again.
> >
> > Both patches were sent at approximately the same time and I think got merged into
> > two separate branches. The conflict resolution [1] then went bad but I didn't notice
> > until weeks later :(
>
> Folks, I have no idea what you are talking about. Can you check that revert
> series [2] gets your change still in? Because I have no clue how it's involved at
> all into discussion.
>
> > [1] https://lore.kernel.org/lkml/20220426150842.473be40e@xxxxxxxxxxxxxxxx/
>
> [2]: https://lore.kernel.org/linux-usb/20220923163051.36288-1-andriy.shevchenko@xxxxxxxxxxxxxxx/
>

Here's Sven's diff:

diff --git a/drivers/usb/dwc3/drd.c b/drivers/usb/dwc3/drd.c
index b60b5f7b6dff4..8cad9e7d33687 100644
--- a/drivers/usb/dwc3/drd.c
+++ b/drivers/usb/dwc3/drd.c
@@ -584,16 +584,15 @@ int dwc3_drd_init(struct dwc3 *dwc)
{
int ret, irq;
+ if (ROLE_SWITCH &&
+ device_property_read_bool(dwc->dev, "usb-role-switch"))
+ return dwc3_setup_role_switch(dwc);
+
dwc->edev = dwc3_get_extcon(dwc);
if (IS_ERR(dwc->edev))
return PTR_ERR(dwc->edev);
- if (ROLE_SWITCH &&
- device_property_read_bool(dwc->dev, "usb-role-switch")) {
- ret = dwc3_setup_role_switch(dwc);
- if (ret < 0)
- return ret;
- } else if (dwc->edev) {
+ if (dwc->edev) {


Here's your revert of my patch:

@@ -538,6 +584,10 @@ int dwc3_drd_init(struct dwc3 *dwc)
 {
        int ret, irq;

+       dwc->edev = dwc3_get_extcon(dwc);
+       if (IS_ERR(dwc->edev))
+               return PTR_ERR(dwc->edev);
+
        if (ROLE_SWITCH &&
            device_property_read_bool(dwc->dev, "usb-role-switch"))
                return dwc3_setup_role_switch(dwc);


There's an order of operations difference. Dwc3_get_extcon() Needs to
be happening after if (ROLE_SWITCH