Re: [PATCH v2 2/2] Revert "usb: dwc3: Don't switch OTG -> peripheral if extcon is present"

From: Ferry Toth
Date: Sun Oct 16 2022 - 16:59:44 EST



Op 15-10-2022 om 21:54 schreef Andrey Smirnov:
On Thu, Oct 13, 2022 at 12:35 PM Ferry Toth <fntoth@xxxxxxxxx> wrote:
<SNIP>
My end goal here is to find a way to test vanilla v6.0 with the two
patches reverted on your end. I thought that during my testing I saw
tusb1210 print those timeout messages during its probe and that
disabling the driver worked to break the loop, but I went back to
double check and it doesn't work so scratch that idea. Configuring
extcon as a built-in breaks host functionality with or without patches
on my end, so I'm not sure it could be a path.

I won't have time to try things with
0043b-TODO-driver-core-Break-infinite-loop-when-deferred-p.patch until
the weekend, meanwhile can you give this diff a try with vanilla (no
reverts) v6.0:

OK, got a chance to try things with that patch. Both v6.0 and v6.0
with my patches reverted work the same, my Kingston DataTraveller USB
stick enumerates and works as expected.

Iow you don't need the patch at all to get usb to work. There has got to be a difference in our configs.

Did you have a chance to look at mine (here: https://drive.google.com/file/d/1aKJWMqiAXnReeLCvxshzjKwGxIWQ7eJk/view?usp=sharing)

Else, send me yours.

modified drivers/phy/ti/phy-tusb1210.c
@@ -127,6 +127,7 @@ static int tusb1210_set_mode(struct phy *phy, enum
phy_mode mode, int submode)
u8 reg;

ret = tusb1210_ulpi_read(tusb, ULPI_OTG_CTRL, &reg);
+ WARN_ON(ret < 0);
if (ret < 0)
return ret;

@@ -152,7 +153,10 @@ static int tusb1210_set_mode(struct phy *phy,
enum phy_mode mode, int submode)
}

tusb->otg_ctrl = reg;
- return tusb1210_ulpi_write(tusb, ULPI_OTG_CTRL, reg);
+ ret = tusb1210_ulpi_write(tusb, ULPI_OTG_CTRL, reg);
+ WARN_ON(ret < 0);
+ return ret;
+
}

#ifdef CONFIG_POWER_SUPPLY

? I'm curious to see if there's masked errors on your end since dwc3
driver doesn't check for those.
root@yuna:~# dmesg | grep -i -E 'warn|assert|error|tusb|dwc3'
8250_mid: probe of 0000:00:04.0 failed with error -16
platform regulatory.0: Direct firmware load for regulatory.db failed
with error -2
brcmfmac mmc2:0001:1: Direct firmware load for
brcm/brcmfmac43340-sdio.Intel Corporation-Merrifield.bin failed with
error -2
sof-audio-pci-intel-tng 0000:00:0d.0: error: I/O region is too small.
sof-audio-pci-intel-tng 0000:00:0d.0: error: failed to probe DSP -19


This is done through configfs only when the switch is set to device mode.
Sure, but can it be disabled? We are looking for unknown variables, so
excluding this would be a reasonable thing to do.
It's not enabled until I flip the switch to device mode.
OK to cut this back and forth short, I think it'd be easier to just
ask you to run what I run. Here's vanilla v6.0 bzImage and initrd
(built with your config + CONFIG_PHY_TUSB1210=y) I tested with

What do you mean by this? My config is with

CONFIG_GENERIC_PHY=y
CONFIG_PHY_TUSB1210=y

https://drive.google.com/drive/folders/1H28AL1coPPZ2kLTYskDuDdWo-oE7DRPH?usp=sharing
let's see how it behaves on your setup. There's also the U-Boot binary

Ok, it's getting weirder and weirder. The following is with my U-Boot and your kernel/initrd

1) I placed them in /boot which is on my btrfs partition on the emmc (my U-Boot has btrfs enabled)

Linux kernel version 6.0.0-edison-acpi-standard (andreysm@neptunefw-builder) #8 SMP PREEMPT_DYNAMIC Sat Oct 15 18:47:19 UTC 2022
Building boot_params at 0x00090000
Loading bzImage at address 100000 (12064480 bytes)
Initial RAM disk at linear address 0x06000000, size 25165824 bytes
Kernel command line: "quiet root=/dev/mmcblk0p8 rootflags=subvol=@,compress=lzo rootfstype=btrfs console=ttyS2,115200n8 earlyprintk=ttyS2,115200n8,keep loglevel=4 systemd.unit=multi-user.target"
Kernel loaded at 00100000, setup_base=00090000

Usb drive is not detected regardless booting with stick plugged or plugging later on.

# lsusb
Bus 001 Device 001: ID 1d6b:0002
Bus 002 Device 001: ID 1d6b:0003

No TUSB1210 probed

# dmesg | grep dwc3
#

2) I placed them in my vfat rescue partition

Linux kernel version 6.0.0-edison-acpi-standard (andreysm@neptunefw-builder) #8 SMP PREEMPT_DYNAMIC Sat Oct 15 18:47:19 UTC 2022
Building boot_params at 0x00090000
Loading bzImage at address 100000 (12064480 bytes)
Initial RAM disk at linear address 0x06000000, size 25165824 bytes
Kernel command line: "debugshell=0 tty1 console=ttyS2,115200n8 root=/dev/mmcblk0p7 rootfstype=vfat systemd.unit=multi-user.target"
Kernel loaded at 00100000, setup_base=00090000

Usb drive is detected.

# lsusb
Bus 001 Device 001: ID 1d6b:0002
Bus 001 Device 002: ID 125f:312b
Bus 002 Device 001: ID 1d6b:0003

TUSB1210 probed

# dmesg | grep dwc3
[    8.605845] tusb1210 dwc3.0.auto.ulpi: GPIO lookup for consumer reset
[    8.605876] tusb1210 dwc3.0.auto.ulpi: using ACPI for GPIO lookup
[    8.605927] tusb1210 dwc3.0.auto.ulpi: using lookup tables for GPIO lookup
[    8.605941] tusb1210 dwc3.0.auto.ulpi: No GPIO consumer reset found
[    8.605956] tusb1210 dwc3.0.auto.ulpi: GPIO lookup for consumer cs
[    8.605970] tusb1210 dwc3.0.auto.ulpi: using ACPI for GPIO lookup
[    8.606011] tusb1210 dwc3.0.auto.ulpi: using lookup tables for GPIO lookup
[    8.606024] tusb1210 dwc3.0.auto.ulpi: No GPIO consumer cs found
[    8.669317] tusb1210 dwc3.0.auto.ulpi: error -110 writing val 0x41 to reg 0x80

## note: options debugshell, root and rootfstype are normally handled by a script in my initrd, so I guess here noop.

I use in that folder in case you want to give it a try.

Now on Merrifield dwc3_get_extcon() doesn't do anything but call
extcon_get_extcon_dev() which doesn't touch any hardware or interact
with other drivers, so assuming

So current v6.0 has: dwc3_get_extcon - dwc3_get_dr_mode - ... -
dwc3_core_init - .. - dwc3_core_init_mode (not working)

I changed to: dwc3_get_dr_mode - dwc3_get_extcon - .. - dwc3_core_init -
.. - dwc3_core_init_mode (no change)

Then to: dwc3_get_dr_mode - .. - dwc3_core_init - .. - dwc3_get_extcon -
dwc3_core_init_mode (works)
still holds(did you double check that with vanilla v6.0?) the only
I didn't check
difference that I can see is execution timings. It seems to me it's
either an extra delay added by execution of extcon_get_extcon_dev()
(unlikely) or multiple partial probes that include dwc3_core_init()
that change things. You can try to check the latter by adding an
artificial probe deferral point after dwc3_core_init(). Something like
(didn't test this):

modified drivers/usb/dwc3/core.c
@@ -1860,6 +1860,10 @@ static int dwc3_probe(struct platform_device *pdev)
goto err3;

ret = dwc3_core_init(dwc);
+ static int deferral_counter = 0;
+ if (deferral_counter++ < 9) /* I counted 9 deferrals in my testing */
+ ret = -EPROBE_DEFER;
+
if (ret) {
dev_err_probe(dev, ret, "failed to initialize core\n");
goto err4;

Not sure how you wanted this tested. So I assume on vanilla booting from btrfs on eemc. It crashes but maybe the trace is usefull. After crash it continues but no USB appears at all.

[    4.185151] kobject_add_internal failed for dwc3.0.auto.ulpi with -EEXIST, don't try to register things with the same name in the same directory.
[    4.198625] dwc3 dwc3.0.auto: failed to register ULPI interface
[    4.213112] BUG: kernel NULL pointer dereference, address: 0000000000000001

[    4.220260] #PF: supervisor read access in kernel mode
[    4.225523] #PF: error_code(0x0000) - not-present page
[    4.230785] PGD 0 P4D 0
[    4.233402] Oops: 0000 [#1] PREEMPT SMP PTI
[    4.237696] CPU: 0 PID: 8 Comm: kworker/u4:0 Not tainted 6.0.0-edison-acpi-standard #1
[    4.245802] Hardware name: Intel Corporation Merrifield/BODEGA BAY, BIOS 542 2015.01.21:18.19.48
[    4.254791] Workqueue: events_unbound deferred_probe_work_func
[    4.260793] RIP: 0010:strlen+0x0/0x20
[    4.264559] Code: b6 07 38 d0 74 14 48 83 c7 01 84 c0 74 05 48 39 f7 75 ec 31 c0 c3 cc cc cc cc 48 89 f8 c3 cc cc cc cc 0f 1f 84 00 00 00 00 00 <80> 3f 00 74 14 48 89 f8 48 83 c0 01 80 38 00 75 f7 48 29 f8 c3 cc
[    4.283751] RSP: 0018:ffffa9520004bb10 EFLAGS: 00010202
[    4.289113] RAX: 0000000000000018 RBX: ffff9c5807d77c18 RCX: 0000000000000000
[    4.296417] RDX: ffffa9520004bb88 RSI: 0000000000000cc0 RDI: 0000000000000001
[    4.303719] RBP: 0000000000000001 R08: 0000000000000000 R09: ffffa9520004baf0
[    4.311022] R10: ffffffffffffffff R11: 000000000000000b R12: 0000000000000cc0
[    4.318323] R13: ffff9c5807d77c18 R14: ffff9c5807d77c18 R15: 000000000000a710
[    4.325625] FS:  0000000000000000(0000) GS:ffff9c583e200000(0000) knlGS:0000000000000000
[    4.333907] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    4.339793] CR2: 0000000000000001 CR3: 000000001540c000 CR4: 00000000001006f0
[    4.347098] Call Trace:
[    4.349611]  <TASK>
[    4.351771]  kstrdup_const+0x2d/0x70
[    4.355453]  kobject_set_name_vargs+0x1e/0x90
[    4.359939]  dev_set_name+0x4e/0x70
[    4.363534]  device_add+0x5b/0x960
[    4.367036]  ? complete_all+0x1b/0x80
[    4.370808]  ulpi_register_interface+0x213/0x290
[    4.375551]  dwc3_ulpi_init+0x17/0x40
[    4.379314]  dwc3_core_init+0xc29/0x1b70
[    4.383350]  dwc3_probe+0x115a/0x1900
[    4.387122]  platform_probe+0x3a/0xa0
[    4.390892]  really_probe+0xdc/0x390
[    4.394567]  ? pm_runtime_barrier+0x4b/0x80
[    4.398867]  __driver_probe_device+0x73/0x170
[    4.403340]  driver_probe_device+0x19/0x90
[    4.407545]  __device_attach_driver+0x80/0x110
[    4.412105]  ? driver_allows_async_probing+0x60/0x60
[    4.417195]  ? driver_allows_async_probing+0x60/0x60
[    4.422286]  bus_for_each_drv+0x79/0xc0
[    4.426230]  __device_attach+0xb7/0x210
[    4.430169]  bus_probe_device+0x89/0xa0
[    4.434111]  deferred_probe_work_func+0x85/0xe0
[    4.438762]  process_one_work+0x1d7/0x3a0
[    4.440890] EXT4-fs (mmcblk1): recovery complete
[    4.442785]  worker_thread+0x48/0x3c0
[    4.442809]  ? rescuer_thread+0x380/0x380
[    4.442828]  kthread+0xe2/0x110
[    4.447489] EXT4-fs (mmcblk1): mounted filesystem with ordered data mode. Quota mode: none.
[    4.451086]  ? kthread_complete_and_exit+0x20/0x20
[    4.451107]  ret_from_fork+0x22/0x30
[    4.475811]  </TASK>
[    4.478052] Modules linked in: mmc_block extcon_intel_mrfld sdhci_pci cqhci sdhci led_class mmc_core intel_soc_pmic_mrfld btrfs libcrc32c xor zlib_deflate raid6_pq zstd_compress
[    4.494312] CR2: 0000000000000001
[    4.497717] ---[ end trace 0000000000000000 ]---