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Wayne Chang 1db527f0cb phy: tegra: xusb: Use a bitmask for UTMI pad power state tracking
commit b47158fb42 upstream.

The current implementation uses bias_pad_enable as a reference count to
manage the shared bias pad for all UTMI PHYs. However, during system
suspension with connected USB devices, multiple power-down requests for
the UTMI pad result in a mismatch in the reference count, which in turn
produces warnings such as:

[  237.762967] WARNING: CPU: 10 PID: 1618 at tegra186_utmi_pad_power_down+0x160/0x170
[  237.763103] Call trace:
[  237.763104]  tegra186_utmi_pad_power_down+0x160/0x170
[  237.763107]  tegra186_utmi_phy_power_off+0x10/0x30
[  237.763110]  phy_power_off+0x48/0x100
[  237.763113]  tegra_xusb_enter_elpg+0x204/0x500
[  237.763119]  tegra_xusb_suspend+0x48/0x140
[  237.763122]  platform_pm_suspend+0x2c/0xb0
[  237.763125]  dpm_run_callback.isra.0+0x20/0xa0
[  237.763127]  __device_suspend+0x118/0x330
[  237.763129]  dpm_suspend+0x10c/0x1f0
[  237.763130]  dpm_suspend_start+0x88/0xb0
[  237.763132]  suspend_devices_and_enter+0x120/0x500
[  237.763135]  pm_suspend+0x1ec/0x270

The root cause was traced back to the dynamic power-down changes
introduced in commit a30951d31b ("xhci: tegra: USB2 pad power controls"),
where the UTMI pad was being powered down without verifying its current
state. This unbalanced behavior led to discrepancies in the reference
count.

To rectify this issue, this patch replaces the single reference counter
with a bitmask, renamed to utmi_pad_enabled. Each bit in the mask
corresponds to one of the four USB2 PHYs, allowing us to track each pad's
enablement status individually.

With this change:
  - The bias pad is powered on only when the mask is clear.
  - Each UTMI pad is powered on or down based on its corresponding bit
    in the mask, preventing redundant operations.
  - The overall power state of the shared bias pad is maintained
    correctly during suspend/resume cycles.

The mutex used to prevent race conditions during UTMI pad enable/disable
operations has been moved from the tegra186_utmi_bias_pad_power_on/off
functions to the parent functions tegra186_utmi_pad_power_on/down. This
change ensures that there are no race conditions when updating the bitmask.

Cc: stable@vger.kernel.org
Fixes: a30951d31b ("xhci: tegra: USB2 pad power controls")
Signed-off-by: Wayne Chang <waynec@nvidia.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20250408030905.990474-1-waynec@nvidia.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2025-05-22 14:29:49 +02:00
arch arm64: dts: rockchip: Remove overdrive-mode OPPs from RK3588J SoC dtsi 2025-05-22 14:29:48 +02:00
block blk-mq: create correct map for fallback case 2025-05-09 09:50:48 +02:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto crypto: Kconfig - Select LIB generic option 2025-05-02 07:59:33 +02:00
Documentation netlink: specs: tc: all actions are indexed arrays 2025-05-22 14:29:42 +02:00
drivers phy: tegra: xusb: Use a bitmask for UTMI pad power state tracking 2025-05-22 14:29:49 +02:00
fs btrfs: add back warning for mount option commit values exceeding 300 2025-05-22 14:29:45 +02:00
include Drivers: hv: vmbus: Remove vmbus_sendpacket_pagebuffer() 2025-05-22 14:29:48 +02:00
init rust: clean Rust 1.88.0's unnecessary_transmutes lint 2025-05-18 08:24:51 +02:00
io_uring io_uring: always arm linked timeouts prior to issue 2025-05-18 08:24:57 +02:00
ipc ipc: fix memleak if msg_init_ns failed in create_ipc_ns 2024-12-05 14:03:02 +01:00
kernel ftrace: Fix preemption accounting for stacktrace filter command 2025-05-22 14:29:48 +02:00
lib crypto: lib/Kconfig - Hide arch options from user 2025-05-02 07:59:32 +02:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm mm: page_alloc: speed up fallbacks in rmqueue_bulk() 2025-05-18 08:24:57 +02:00
net net/tls: fix kernel panic when alloc_page failed 2025-05-22 14:29:43 +02:00
rust rust: clean Rust 1.88.0's clippy::uninlined_format_args lint 2025-05-18 08:24:57 +02:00
samples tracing: samples: Initialize trace_array_printk() with the correct function 2025-05-22 14:29:48 +02:00
scripts kbuild: Disable -Wdefault-const-init-unsafe 2025-05-22 14:29:48 +02:00
security landlock: Prepare to add second errata 2025-04-20 10:15:56 +02:00
sound ALSA: usb-audio: Add sample rate quirk for Microdia JP001 USB Camera 2025-05-22 14:29:47 +02:00
tools vsock/test: Fix occasional failure in SIOCOUTQ tests 2025-05-22 14:29:41 +02:00
usr kbuild: hdrcheck: fix cross build with clang 2025-03-13 13:02:18 +01:00
virt KVM: Add member to struct kvm_gfn_range to indicate private/shared 2025-05-22 14:29:36 +02:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.clippy.toml rust: clean Rust 1.88.0's warning about clippy::disallowed_macros configuration 2025-05-18 08:24:51 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore rust: introduce .clippy.toml 2025-03-13 13:01:42 +01:00
.mailmap mailmap: add entry for Thorsten Blum 2024-11-07 14:14:59 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Remove self from DSA entry 2024-11-03 12:52:38 -08:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: Update Alexey Makhalov's email address 2025-05-22 14:29:46 +02:00
Makefile Linux 6.12.29 2025-05-18 08:25:00 +02:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.