> On Fri, 2020-06-19 at 02:05 +0000, Peter Chen wrote:
> >
> > >
> > > 1st problem - RNDIS
> > > We try to use RNDIS on one of the USB ports the Colibri iMX6ULL has.
> > > For this
> > > purpose I'm using the usb_f_rndis.ko kernel module and setting
> > > dr_mode of
> > > &usbotg1 to "peripheral"
> > > This works fine on iMX7 but does not on iMX6ULL. On the ULL board I
> > > can see a "ci_hdrc.0" in /sys/class/udc after boot. If I add now an
> > > USB GPIO extcon to usbotg this changes to "ci_hdrc.1" and everything
> > > works fine after boot, but not after unplugging USB and replugging.
> > > To setup RNDIS I use the commands [1] I put at the end of this email
> > > for reference.
> > >
> >
> > If the board designs for USB part are the same between iMX7 version
> > and iMX6ULL version, keep dts content are the same except for the USB
> > PHY port (including the phandle for it), these two SoCs uses the
> > different USB PHY.
>
> Thanks for this hint! Then here may something be different or not quite right yet (for
> our usecase).
>
> I saw that in phy-mxs-usb.c there is no "mode" in struct mxs_phy like it is on
> downstream code. I couldn't find how the code switches the PHY to peripheral
> mode.
>
> Should it even be possible with this phy to use dr_mode = "peripheral"?
>
No, this mode is set at udc.c, it may be not related to your failure use case.
Try to debug at probe function, and see what's the difference.
> >
> > If the RNDIS could work at the first time, it seems your configfs
> > script should be OK.
> >
> > > 2nd problem - constant resetting
> > > When I compile a plain mainline kernel with "imx_v6_v7_defconfig"
> > > and boot the
> > > iMX6ULL with it I see that the USB is constantly resetting the hub
> > > that is present on the Colibri Evaluation carrier board.
> > >
> > > [ 49.654621] usb 1-1: reset high-speed USB device number 2 using
> > > ci_hdrc
> > > [ 52.180781] usb 1-1: reset high-speed USB device number 2 using
> > > ci_hdrc
> > > [ 54.699678] usb 1-1: reset high-speed USB device number 2 using
> > > ci_hdrc
> > >
> >
> > Try to add external power to the USB HUB avoid the board can't supply
> > enough power.
> > If not, try to disable runtime pm, and see if it works.
> >
> > 59 static const struct ci_hdrc_imx_platform_flag imx6ul_usb_data = {
> > 60 .flags = CI_HDRC_SUPPORTS_RUNTIME_PM |
> > 61 CI_HDRC_TURN_VBUS_EARLY_ON,
> > 62 };
> > 63
>
> The power is no problem. The usb-hub is soldered to the carrier-board, I measured
> it and voltage is rock solid. We use an USB2514 chip.
>
> Thanks for the hint, disabling CI_HDRC_SUPPORTS_RUNTIME_PM solves the
> issue.
>
Try to port this patch from downstream BSP.
commit 5840b174e85e66b502b4887026ce44c5665c29b1
Author: Li Jun <jun.li@xxxxxxx>
Date: Mon Oct 16 23:13:19 2017 +0800
MLK-16576 usb: phy: mxs: set hold_ring_off for USB2 PLL power up
USB2 PLL use ring VCO, when the PLL power up, the ring VCO’s supply also
ramp up. There is a possibility that the ring VCO start oscillation at
multi nodes in this phase, especially for VCO which has many stages, then
the multiwave will kept until PLL power down. Hold_ring_off(bit11) can
force the VCO in one determined state when VCO supply start ramp up, to
avoid this multiwave issue. Per IC design's suggestion it's better this
bit can be off from 25us after pll power up to 25us before USB TX/RX.
Acked-by: Peter Chen <peter.chen@xxxxxxx>
Signed-off-by: Li Jun <jun.li@xxxxxxx>
Peter
