[PATCH] ARM: dts: imx6qdl-udoo: Disable USB host to work around boot issues

[PATCH] ARM: dts: imx6qdl-udoo: Disable USB host to work around boot issues

[Mark Brown]

Attempting to boot my Udoo Dual and Quad with mainline hangs during boot
after printing:

[    3.270471] imx_usb 2184000.usb: No over current polarity defined
[    3.922502] mxs_phy 20c9000.usbphy: Data pin can't make good contact.
[    3.940097] imx_usb 2184200.usb: No over current polarity defined

where imx_usb 2184200.usb is usbh1 in the DT. Adding debug prints to the
code seems to show that we lock up at the first read in usbmisc_imx6q_init()
which in combination with the above logging about the USB controllers
suggests that we lock up on the first read in usbmisc_imx6q_init(). Looking
at some of the other i.MX6 boards and the warning messages that are being
printed suggests that there is bitrot in the DTS for the device so disable
it for now, with it disabled the board boots successfully.  Clearly this is
not a real fix, but it does allow some use of the board with mainline.

Similar behaviour is seen all the way back as far as v4.19, I tried going
back to when the board was added but had toolchain issues. Vendor provided
binaries seem fine on the boards so it seems likely that the hardware is
fine and the issue is with some combination of the DT and kernel.  This
should obviously be resolved properly but for now this at least allows
the kernel to boot with reduced functionality on these systems.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 arch/arm/boot/dts/imx6qdl-udoo.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/imx6qdl-udoo.dtsi b/arch/arm/boot/dts/imx6qdl-udoo.dtsi
index ccfa8e320be6..93a8123da27d 100644
--- a/arch/arm/boot/dts/imx6qdl-udoo.dtsi
+++ b/arch/arm/boot/dts/imx6qdl-udoo.dtsi
@@ -295,7 +295,7 @@ &usbh1 {
 	pinctrl-0 = <&pinctrl_usbh>;
 	vbus-supply = <&reg_usb_h1_vbus>;
 	clocks = <&clks IMX6QDL_CLK_CKO>;
-	status = "okay";
+	status = "disabled";
 };
 
 &usbotg {
-- 
2.30.2


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Re: [PATCH] ARM: dts: imx6qdl-udoo: Disable USB host to work around boot issues

[Fabio Estevam]

[Adding Baruch and Josua]

On Sun, May 1, 2022 at 2:47 PM Mark Brown <broonie@kernel.org> wrote:
>
> Attempting to boot my Udoo Dual and Quad with mainline hangs during boot
> after printing:
>
> [    3.270471] imx_usb 2184000.usb: No over current polarity defined
> [    3.922502] mxs_phy 20c9000.usbphy: Data pin can't make good contact.
> [    3.940097] imx_usb 2184200.usb: No over current polarity defined
>
> where imx_usb 2184200.usb is usbh1 in the DT. Adding debug prints to the
> code seems to show that we lock up at the first read in usbmisc_imx6q_init()
> which in combination with the above logging about the USB controllers
> suggests that we lock up on the first read in usbmisc_imx6q_init(). Looking
> at some of the other i.MX6 boards and the warning messages that are being
> printed suggests that there is bitrot in the DTS for the device so disable
> it for now, with it disabled the board boots successfully.  Clearly this is
> not a real fix, but it does allow some use of the board with mainline.
>
> Similar behaviour is seen all the way back as far as v4.19, I tried going
> back to when the board was added but had toolchain issues. Vendor provided
> binaries seem fine on the boards so it seems likely that the hardware is
> fine and the issue is with some combination of the DT and kernel.  This
> should obviously be resolved properly but for now this at least allows
> the kernel to boot with reduced functionality on these systems.

My imx6-cubox is no longer functional, so I cannot verify this myself.

Baruch and Josua,

Are you aware of this issue?

Thanks

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Re: [PATCH] ARM: dts: imx6qdl-udoo: Disable USB host to work around boot issues

[Fabio Estevam]

On Sun, May 1, 2022 at 7:35 PM Fabio Estevam <festevam@gmail.com> wrote:
>
> [Adding Baruch and Josua]
>
> On Sun, May 1, 2022 at 2:47 PM Mark Brown <broonie@kernel.org> wrote:
> >
> > Attempting to boot my Udoo Dual and Quad with mainline hangs during boot
> > after printing:
> >
> > [    3.270471] imx_usb 2184000.usb: No over current polarity defined
> > [    3.922502] mxs_phy 20c9000.usbphy: Data pin can't make good contact.
> > [    3.940097] imx_usb 2184200.usb: No over current polarity defined
> >
> > where imx_usb 2184200.usb is usbh1 in the DT. Adding debug prints to the
> > code seems to show that we lock up at the first read in usbmisc_imx6q_init()
> > which in combination with the above logging about the USB controllers
> > suggests that we lock up on the first read in usbmisc_imx6q_init(). Looking
> > at some of the other i.MX6 boards and the warning messages that are being
> > printed suggests that there is bitrot in the DTS for the device so disable
> > it for now, with it disabled the board boots successfully.  Clearly this is
> > not a real fix, but it does allow some use of the board with mainline.
> >
> > Similar behaviour is seen all the way back as far as v4.19, I tried going
> > back to when the board was added but had toolchain issues. Vendor provided
> > binaries seem fine on the boards so it seems likely that the hardware is
> > fine and the issue is with some combination of the DT and kernel.  This
> > should obviously be resolved properly but for now this at least allows
> > the kernel to boot with reduced functionality on these systems.
>
> My imx6-cubox is no longer functional, so I cannot verify this myself.
>
> Baruch and Josua,
>
> Are you aware of this issue?

Oops, sorry for the confusion. It's an udoo board, not a cubox.

Mark, I recall I sent this some time ago:
https://patchwork.kernel.org/project/linux-arm-kernel/patch/1516278858-15464-1-git-send-email-fabio.estevam@nxp.com/

And I still carry this patch in Buildroot to avoid the kernel hang:
https://github.com/buildroot/buildroot/blob/master/board/udoo/mx6qdl/patches/linux/0000-udoo-disable-usbh1.patch

I still think we need it:

Reviewed-by: Fabio Estevam <festevam@gmail.com>

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Re: [PATCH] ARM: dts: imx6qdl-udoo: Disable USB host to work around boot issues

[Shawn Guo]

On Sun, May 01, 2022 at 06:47:13PM +0100, Mark Brown wrote:
> Attempting to boot my Udoo Dual and Quad with mainline hangs during boot
> after printing:
> 
> [    3.270471] imx_usb 2184000.usb: No over current polarity defined
> [    3.922502] mxs_phy 20c9000.usbphy: Data pin can't make good contact.
> [    3.940097] imx_usb 2184200.usb: No over current polarity defined
> 
> where imx_usb 2184200.usb is usbh1 in the DT. Adding debug prints to the
> code seems to show that we lock up at the first read in usbmisc_imx6q_init()
> which in combination with the above logging about the USB controllers
> suggests that we lock up on the first read in usbmisc_imx6q_init(). Looking
> at some of the other i.MX6 boards and the warning messages that are being
> printed suggests that there is bitrot in the DTS for the device so disable
> it for now, with it disabled the board boots successfully.  Clearly this is
> not a real fix, but it does allow some use of the board with mainline.
> 
> Similar behaviour is seen all the way back as far as v4.19, I tried going
> back to when the board was added but had toolchain issues. Vendor provided
> binaries seem fine on the boards so it seems likely that the hardware is
> fine and the issue is with some combination of the DT and kernel.  This
> should obviously be resolved properly but for now this at least allows
> the kernel to boot with reduced functionality on these systems.
> 
> Signed-off-by: Mark Brown <broonie@kernel.org>

Applied, thanks!

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