On Thu, Apr 27, 2023 at 10:54 AM Adam Ford aford173@gmail.com wrote:
On Thu, Apr 27, 2023 at 12:52 PM Tim Harvey tharvey@gateworks.com wrote:
On Thu, Apr 27, 2023 at 10:49 AM Fabio Estevam festevam@gmail.com wrote:
Hi Adam,
On Thu, Apr 27, 2023 at 2:42 PM Adam Ford aford173@gmail.com wrote:
There was some re-organization of the power domains in Linux in the device tree [1]. Do you know if those propagated to U-Boot?
Excellent, I just synced the kernel imx8mm.dtsi with U-Boot and it does fix the "ums 0 mmc 1" issue I just described.
I will submit the dtsi sync patch. Thanks!
Fabio,
The original issue I was trying to solve should not be visible on imx8mm-evk unless you changed its usbotg1 to dr_mode = "host" in which case you should see a hang with a simple 'usb start && usb stop'.
If you leave it without the "host" but connect a device to the port with a host adapter, do you get the same behavior?
Adam,
Yes, simply adding a USB OTG (or USB-C) to host cable (even without a device attached) will cause the hang.
The issue here is that ehci-mx6.c:ehci_usb_remove calls ehci_deregister which calls ehci_shutdown which accesses the EHCI registers to suspend the ports (after the imx8m power domains are disabled) which causes the hang. This is not called if the controller is not in host mode.
Tim