Re: DWC3 host support

[Angus Ainslie <angus@akkea.ca>]

Hi Marek/Michal,

On 2022-07-18 01:13, Michal Simek wrote:
> On 7/17/22 17:23, Marek Vasut wrote:
>> On 7/17/22 05:00, Angus Ainslie wrote:
>>> On 2022-07-16 11:37, Marek Vasut wrote:
>>>> On 7/16/22 15:02, Angus Ainslie wrote:
>>>>> Hi Michal,
>>>>> 
>>>>> I recently rebased my librem5 tree onto the latest u-boot-imx 
>>>>> branch
>>>>> and the dwc3 host mode stopped working.
>>>>> 
>>>>> I bisected it down to this commit:
>>>>> 
>>>>> 142d50fbce7c364a74f5e8204dba491b9f066e6c usb: dwc3: Add support for
>>>>> usb3-phy PHY configuration
>>>>> 
>>>>> Reverting that commit allows usb host mode to work on the librem5 
>>>>> again.
>>>>> 
>>>>> Should this initialization go into an SOC specific glue_configure
>>>>> function ?
>>>>> 
>>>>> Is the imx8mq.dtsi missing something that will keep usb host 
>>>>> working
>>>>> with this patch ?
>>>>> 
>>>>> Does this break usb host on other imx8mq devices ?
>>>> 
>>>> Wasn't this fixed by:
>>>> 868d58f69c ("usb: dwc3: Fix non-usb3 configurations")
>>>> ?
>>> 
>>> I've got that in my tree and it still fails to probe the USB2 hub and
>>> USB 2 storage.
>> 
>> I assume you do have CONFIG_PHY_IMX8MQ_USB enabled ?
>> 
>> What does generic_phy_get_by_name() return for you in
>> drivers/usb/dwc3/dwc3-generic.c ?
> 
> As Marek said there was one patch which fixes origin patch which
> didn't handle all the error cases properly. We need to know return
> value from generic_phy_get_by_name(), also if you still have usb3-phy
> in DT (as is in imx8mq.dtsi) with phy DT status enabled and enabled
> phy driver (CONFIG_PHY_IMX8MQ_USB).
> 

I use the imx8mq.dtsi from the u-boot-imx tree that includes the 
usb3-phy

https://source.denx.de/u-boot/custodians/u-boot-imx/-/blob/master/arch/arm/dts/imx8mq.dtsi#L1421

CONFIG_PHY_IMX8MQ_USB is defined in my defconfig

https://source.puri.sm/angus.ainslie/uboot-imx/-/blob/upstream/librem5-uart2/configs/librem5_defconfig#L114

Here is the error path I think you're talking about

https://source.puri.sm/angus.ainslie/uboot-imx/-/blob/upstream/librem5-uart2/drivers/usb/dwc3/dwc3-generic.c#L474

I modified dwc3-generic.c to print the return value

@@ -475,6 +477,8 @@ static int dwc3_glue_probe(struct udevice *dev)
                 phy.dev = NULL;
         }

+       debug("phy3 initialized %d %s\n", ret, phy.dev ? phy.dev->name : 
"null");
+
         glue->regs = dev_read_addr(dev);

Here's the output from the boot

U-Boot 2022.07-rc5-00014-g329f8a8ae05-dirty (Jul 18 2022 - 06:59:45 
-0700)

CPU:   Freescale i.MX8MQ rev2.0 1500 MHz (running at 1000 MHz)
CPU:   Commercial temperature grade (0C to 95C) at 35C
Reset cause: POR
Model: Purism Librem 5r4
DRAM:  3 GiB
dwc3_glue_bind: subnode name: port@0
dwc3_glue_bind: dr_mode: OTG or Peripheral
dwc3_glue_bind: subnode name: port@1
dwc3_glue_bind: dr_mode: OTG or Peripheral
dwc3_glue_bind: subnode name: hub@1
dwc3_glue_bind: dr_mode: HOST
clk_register: failed to get <NULL> device (parent of ckil)
clk_register: failed to get <NULL> device (parent of clock-osc-27m)
clk_register: failed to get <NULL> device (parent of sys1_pll)
clk_register: failed to get <NULL> device (parent of sys2_pll)
clk_register: failed to get <NULL> device (parent of sys3_pll)
Enabling regulator-hub
tps65982 boot successful
Core:  192 devices, 25 uclasses, devicetree: separate
MMC:   FSL_SDHC: 0, FSL_SDHC: 1
Loading Environment from MMC... OK
In:    serial
Out:   serial
Err:   serial
Board name: librem5
Board rev:  4
vol_down_key_pressed : 1
Net:   No ethernet found.
Hit any key to stop autoboot:  0
u-boot=> usb start
starting USB...
Bus hub@1: generic_phy_get_by_name(dev=00000000ffb19830, name=usb3-phy, 
phy=00000000ffb08460)
generic_phy_get_by_index_nodev(node=usb@38200000, index=1, 
phy=00000000ffb08460)
generic_phy_xlate_offs_flags(phy=00000000ffb08460)
phy3 initialized 0 usb-phy@382f0040
phy3 powered on
dwc3_glue_probe finished
generic_phy_get_by_index_nodev(node=usb@38200000, index=0, 
phy=00000000ffb2b1e0)
generic_phy_xlate_offs_flags(phy=00000000ffb2b1e0)
generic_phy_get_by_index_nodev(node=usb@38200000, index=1, 
phy=00000000ffb2b1f0)
generic_phy_xlate_offs_flags(phy=00000000ffb2b1f0)
dwc3-generic-host hub@1: Event buf 00000000ffb2b340 dma ffb2b340 length 
256
Register 2000140 NbrPorts 2
Starting the controller
USB XHCI 1.10
scanning bus hub@1 for devices... cannot reset port 1!?
1 USB Device(s) found
        scanning usb for storage devices... 0 Storage Device(s) found
u-boot=> usb info
1: Hub,  USB Revision 3.0
  - U-Boot XHCI Host Controller
  - Class: Hub
  - PacketSize: 512  Configurations: 1
  - Vendor: 0x0000  Product 0x0000 Version 1.0
    Configuration: 1
    - Interfaces: 1 Self Powered 0mA
      Interface: 0
      - Alternate Setting 0, Endpoints: 1
      - Class Hub
      - Endpoint 1 In Interrupt MaxPacket 8 Interval 255ms

Thanks
Angus

> Thanks,
> Michal