[Bug 219626] New: Infinite udev uevent stream from USB-C port

[Bug 219626] New: Infinite udev uevent stream from USB-C port

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=219626

            Bug ID: 219626
           Summary: Infinite udev uevent stream from USB-C port
           Product: Drivers
           Version: 2.5
          Hardware: Intel
                OS: Linux
            Status: NEW
          Severity: normal
          Priority: P3
         Component: USB
          Assignee: drivers_usb@kernel-bugs.kernel.org
          Reporter: hegel666@gmail.com
                CC: gsara1989@gmail.com
        Regression: Yes
           Bisected fa48d7e81624efdf398b990a9049e9cd75a5aead
         commit-id:

Created attachment 307397
  --> https://bugzilla.kernel.org/attachment.cgi?id=307397&action=edit
udevadm monitor output

After updating to 6.12.5 from 6.12.4 systemd-udevd worker burns CPU processing
an infinite stream of USB-C events. In order to reproduce I have to plug off
the USB cable and plug it in again. I tried 6.12.6 kernel with the same buggy
result. The problem disappears after going back to 6.12.4.

My machine is an ASUS Zenbook UM5302TA laptop.

Reverting this commit fixes the issue:

commit c0ca6fd5f6ebde8fc0df8bb5c32629d1284f60d0
Author: Saranya Gopal <saranya.gopal@intel.com>
Date:   Fri Aug 30 14:13:42 2024 +0530

    usb: typec: ucsi: Do not call ACPI _DSM method for UCSI read operations

    [ Upstream commit fa48d7e81624efdf398b990a9049e9cd75a5aead ]

    ACPI _DSM methods are needed only for UCSI write operations and for reading
    CCI during RESET_PPM operation. So, remove _DSM calls from other places.
    While there, remove the Zenbook quirk also since the default behavior
    now aligns with the Zenbook quirk. With this change, GET_CONNECTOR_STATUS
    returns at least 6 seconds faster than before in Arrowlake-S platforms.

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[Bug 219626] Infinite udev uevent stream from USB-C port

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=219626

--- Comment #1 from Marcin Bachry (hegel666@gmail.com) ---
Here's a minimal revert required to fix the issue:

> diff --git a/drivers/usb/typec/ucsi/ucsi_acpi.c
> b/drivers/usb/typec/ucsi/ucsi_acpi.c
> index accf15ff1306..0e28ea57c611 100644
> --- a/drivers/usb/typec/ucsi/ucsi_acpi.c
> +++ b/drivers/usb/typec/ucsi/ucsi_acpi.c
> @@ -61,11 +61,9 @@ static int ucsi_acpi_read_cci(struct ucsi *ucsi, u32 *cci)
>       struct ucsi_acpi *ua = ucsi_get_drvdata(ucsi);
>       int ret;
>  
> -     if (UCSI_COMMAND(ua->cmd) == UCSI_PPM_RESET) {
> -             ret = ucsi_acpi_dsm(ua, UCSI_DSM_FUNC_READ);
> -             if (ret)
> -                     return ret;
> -     }
> +     ret = ucsi_acpi_dsm(ua, UCSI_DSM_FUNC_READ);
> +     if (ret)
> +             return ret;
>  
>       memcpy(cci, ua->base + UCSI_CCI, sizeof(*cci));

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[Bug 219626] Infinite udev uevent stream from USB-C port

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=219626

--- Comment #2 from Marcin Bachry (hegel666@gmail.com) ---
Created attachment 307441
  --> https://bugzilla.kernel.org/attachment.cgi?id=307441&action=edit
minimal reverting change

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