linux-toradex.git/drivers/tty, branch v6.19

serial: Fix not set tty->port race condition

2026-01-23T16:23:09+00:00

Revert commit bfc467db60b7 ("serial: remove redundant
tty_port_link_device()") because the tty_port_link_device() is not
redundant: the tty->port has to be confured before we call
uart_configure_port(), otherwise user-space can open console without TTY
linked to the driver.

This tty_port_link_device() was added explicitly to avoid this exact
issue in commit fb2b90014d78 ("tty: link tty and port before configuring
it as console"), so offending commit basically reverted the fix saying
it is redundant without addressing the actual race condition presented
there.

Reproducible always as tty->port warning on Qualcomm SoC with most of
devices disabled, so with very fast boot, and one serial device being
the console:

  printk: legacy console [ttyMSM0] enabled
  printk: legacy console [ttyMSM0] enabled
  printk: legacy bootconsole [qcom_geni0] disabled
  printk: legacy bootconsole [qcom_geni0] disabled
  ------------[ cut here ]------------
  tty_init_dev: ttyMSM driver does not set tty->port. This would crash the kernel. Fix the driver!
  WARNING: drivers/tty/tty_io.c:1414 at tty_init_dev.part.0+0x228/0x25c, CPU#2: systemd/1
  Modules linked in: socinfo tcsrcc_eliza gcc_eliza sm3_ce fuse ipv6
  CPU: 2 UID: 0 PID: 1 Comm: systemd Tainted: G S                  6.19.0-rc4-next-20260108-00024-g2202f4d30aa8 #73 PREEMPT
  Tainted: [S]=CPU_OUT_OF_SPEC
  Hardware name: Qualcomm Technologies, Inc. Eliza (DT)
  ...
  tty_init_dev.part.0 (drivers/tty/tty_io.c:1414 (discriminator 11)) (P)
  tty_open (arch/arm64/include/asm/atomic_ll_sc.h:95 (discriminator 3) drivers/tty/tty_io.c:2073 (discriminator 3) drivers/tty/tty_io.c:2120 (discriminator 3))
  chrdev_open (fs/char_dev.c:411)
  do_dentry_open (fs/open.c:962)
  vfs_open (fs/open.c:1094)
  do_open (fs/namei.c:4634)
  path_openat (fs/namei.c:4793)
  do_filp_open (fs/namei.c:4820)
  do_sys_openat2 (fs/open.c:1391 (discriminator 3))
  ...
  Starting Network Name Resolution...

Apparently the flow with this small Yocto-based ramdisk user-space is:

driver (qcom_geni_serial.c):                  user-space:
============================                  ===========
qcom_geni_serial_probe()
 uart_add_one_port()
  serial_core_register_port()
   serial_core_add_one_port()
    uart_configure_port()
     register_console()
    |
    |                                         open console
    |                                          ...
    |                                          tty_init_dev()
    |                                           driver->ports[idx] is NULL
    |
    tty_port_register_device_attr_serdev()
     tty_port_link_device() <- set driver->ports[idx]

Fixes: bfc467db60b7 ("serial: remove redundant tty_port_link_device()")
Cc: stable@vger.kernel.org
Signed-off-by: Krzysztof Kozlowski 
Reviewed-by: Jiri Slaby 
Link: https://patch.msgid.link/20260123072139.53293-2-krzysztof.kozlowski@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman

serial: 8250_pci: Fix broken RS485 for F81504/508/512

2026-01-16T13:29:10+00:00

Fintek F81504/508/512 can support both RTS_ON_SEND and RTS_AFTER_SEND,
but pci_fintek_rs485_supported only announces the former.

This makes it impossible to unset SER_RS485_RTS_ON_SEND from
userspace because of uart_sanitize_serial_rs485(). Some devices
with these chips need RTS low on TX, so they are effectively broken.

Fix this by announcing the support for SER_RS485_RTS_AFTER_SEND,
similar to commit 068d35a7be65 ("serial: sc16is7xx: announce support
for SER_RS485_RTS_ON_SEND").

Fixes: 4afeced55baa ("serial: core: fix sanitizing check for RTS settings")
Cc: stable 
Signed-off-by: Marnix Rijnart 
Link: https://patch.msgid.link/20260112000931.61703-1-marnix.rijnart@iwell.eu
Signed-off-by: Greg Kroah-Hartman

serial: qcom_geni: Fix BT failure regression on RB2 platform

2026-01-16T13:28:49+00:00

Commit 10904d725f6e ("serial: qcom-geni: Enable PM runtime for serial
driver") caused BT init to fail during bootup on the RB2 platform,
preventing proper BT initialization. However, BT works correctly after
bootup completes.

The issue occurs when runtime PM is enabled and uart_add_one_port() is
called before wakeup IRQ setup. The uart_add_one_port() call activates
the device through runtime PM, which configures GPIOs to the "qup_x"
pinmux function during runtime resume. When wakeup IRQ registration
happens afterward using dev_pm_set_dedicated_wake_irq(), these GPIOs
are reset back to the "gpio" pinmux function, which impacts the RX GPIO
and leads to Bluetooth failures.

Fix this by ensuring wakeup IRQ setup is completed before calling
uart_add_one_port() to prevent the pinmux function conflict.

Fixes: 10904d725f6e ("serial: qcom-geni: Enable PM runtime for serial driver")
Reported-by: Dmitry Baryshkov 
Closes: https://lore.kernel.org/all/20251110101043.2108414-4-praveen.talari@oss.qualcomm.com/
Tested-by: Dmitry Baryshkov 
Reviewed-by: Dmitry Baryshkov 
Signed-off-by: Praveen Talari 
Link: https://patch.msgid.link/20260108041006.1874757-1-praveen.talari@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman

serial: xilinx_uartps: fix rs485 delay_rts_after_send

2025-12-23T10:55:16+00:00

RTS line control with delay should be triggered when there is no more
bytes in kfifo and hardware buffer is empty. Without this patch RTS
control is scheduled right after feeding hardware buffer and this is too
early.

RTS line may change state before hardware buffer is empty.

With this patch delayed RTS state change is triggered when function
cdns_uart_handle_tx is called from cdns_uart_isr on
CDNS_UART_IXR_TXEMPTY exactly when hardware completed transmission

Fixes: fccc9d9233f9 ("tty: serial: uartps: Add rs485 support to uartps driver")
Cc: stable 
Link: https://patch.msgid.link/20251221103221.1971125-1-jakub.turek@elsta.tech
Signed-off-by: Jakub Turek  
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Check that the DMA cookie is valid

2025-12-23T10:54:00+00:00

The driver updates struct sci_port::tx_cookie to zero right before the TX
work is scheduled, or to -EINVAL when DMA is disabled.
dma_async_is_complete(), called through dma_cookie_status() (and possibly
through dmaengine_tx_status()), considers cookies valid only if they have
values greater than or equal to 1.

Passing zero or -EINVAL to dmaengine_tx_status() before any TX DMA
transfer has started leads to an incorrect TX status being reported, as the
cookie is invalid for the DMA subsystem. This may cause long wait times
when the serial device is opened for configuration before any TX activity
has occurred.

Check that the TX cookie is valid before passing it to
dmaengine_tx_status().

Fixes: 7cc0e0a43a91 ("serial: sh-sci: Check if TX data was written to device in .tx_empty()")
Cc: stable 
Signed-off-by: Claudiu Beznea 
Link: https://patch.msgid.link/20251217135759.402015-1-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman

serial: core: Fix serial device initialization

2025-12-23T10:53:37+00:00

During restoring sysfs fwnode information the information of_node_reused
was dropped. This was previously set by device_set_of_node_from_dev().
Add it back manually

Fixes: 24ec03cc5512 ("serial: core: Restore sysfs fwnode information")
Cc: stable 
Suggested-by: Cosmin Tanislav 
Signed-off-by: Alexander Stein 
Tested-by: Michael Walle 
Tested-by: Marek Szyprowski 
Tested-by: Cosmin Tanislav 
Link: https://patch.msgid.link/20251219152813.1893982-1-alexander.stein@ew.tq-group.com
Signed-off-by: Greg Kroah-Hartman

serial: 8250: longson: Fix NULL vs IS_ERR() bug in probe

2025-12-17T14:11:00+00:00

The devm_platform_get_and_ioremap_resource() function never returns
NULL, it returns error pointers.  Fix the error checking to match.

Fixes: 25e95d763176 ("serial: 8250: Add Loongson uart driver support")
Signed-off-by: Dan Carpenter 
Link: https://patch.msgid.link/aSsIa3KdAlXh5uQC@stanley.mountain
Signed-off-by: Greg Kroah-Hartman

serial: core: Restore sysfs fwnode information

2025-12-17T14:10:46+00:00

The change that restores sysfs fwnode information does it only for OF cases.
Update the fix to cover all possible types of fwnodes.

Fixes: d36f0e9a0002 ("serial: core: restore of_node information in sysfs")
Cc: stable 
Signed-off-by: Andy Shevchenko 
Link: https://patch.msgid.link/20251127163650.2942075-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman

Merge tag 'tty-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

2025-12-07T02:38:19+00:00

Pull tty/serial updates from Greg KH:
 "Here is the big set of tty/serial driver changes for 6.19-rc1. Nothing
  major at all, just small constant churn to make the tty layer
  "cleaner" as well as serial driver updates and even a new test added!
  Included in here are:

   - More tty/serial cleanups from Jiri

   - tty tiocsti test added to hopefully ensure we don't regress in this
     area again

   - sc16is7xx driver updates

   - imx serial driver updates

   - 8250 driver updates

   - new hardware device ids added

   - other minor serial/tty driver cleanups and tweaks

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'tty-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (60 commits)
  serial: sh-sci: Fix deadlock during RSCI FIFO overrun error
  dt-bindings: serial: rsci: Drop "uart-has-rtscts: false"
  LoongArch: dts: Add uart new compatible string
  serial: 8250: Add Loongson uart driver support
  dt-bindings: serial: 8250: Add Loongson uart compatible
  serial: 8250: add driver for KEBA UART
  serial: Keep rs485 settings for devices without firmware node
  serial: qcom-geni: Enable Serial on SA8255p Qualcomm platforms
  serial: qcom-geni: Enable PM runtime for serial driver
  serial: sprd: Return -EPROBE_DEFER when uart clock is not ready
  tty: serial: samsung: Declare earlycon for Exynos850
  serial: icom: Convert PCIBIOS_* return codes to errnos
  serial: 8250-of: Fix style issues in 8250_of.c
  serial: add support of CPCI cards
  serial: mux: Fix kernel doc for mux_poll()
  tty: replace use of system_unbound_wq with system_dfl_wq
  serial: 8250_platform: simplify IRQF_SHARED handling
  serial: 8250: make share_irqs local to 8250_platform
  serial: 8250: move skip_txen_test to core
  serial: drop SERIAL_8250_DEPRECATED_OPTIONS
  ...

Merge tag 'pci-v6.19-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci

2025-12-05T01:29:41+00:00

Pull PCI updates from Bjorn Helgaas:
 "Enumeration:

   - Enable host bridge emulation for PCI_DOMAINS_GENERIC platforms (Dan
     Williams)

   - Switch vmd from custom domain number allocator to the common
     allocator to prevent a potential race with new non-VMD buses (Dan
     Williams)

   - Enable Precision Time Measurement (PTM) only if device advertises
     support for a relevant role, to prevent invalid PTM Requests that
     cause ACS violations that are reported as AER Uncorrectable
     Non-Fatal errors (Mika Westerberg)

  Resource management:

   - Prevent resource tree corruption when BAR resize fails (Ilpo
     Järvinen)

   - Restore BARs to the original size if a BAR resize fails (Ilpo
     Järvinen)

   - Remove BAR release from BAR resize attempts by the xe, i915, and
     amdgpu drivers so the PCI core can restore BARs if the resize fails
     (Ilpo Järvinen)

   - Move Resizable BAR code to rebar.c (Ilpo Järvinen)

   - Add pci_rebar_size_supported() and use it in i915 and xe (Ilpo
     Järvinen)

   - Add pci_rebar_get_max_size() and use it in xe and amdgpu (Ilpo
     Järvinen)

  Power management and error handling:

   - For drivers using PCI legacy suspend, save config state at suspend
     so that state (not any earlier state from enumeration, probe, or
     error recovery) will be restored when resuming (Lukas Wunner)

   - For devices with no driver or a driver that lacks power management,
     save config state at hibernate so that state (not any earlier state
     from enumeration, probe, or error recovery) will be restored when
     resuming (Lukas Wunner)

   - Save device config space on device addition, before driver binding,
     so error recovery works more reliably (Lukas Wunner)

   - Drop pci_save_state() from several drivers that no longer need it
     since the PCI core always does it and pci_restore_state() no longer
     invalidates the saved state (Lukas Wunner)

   - Document use of pci_save_state() by drivers to capture the state
     they want restored during error recovery (Lukas Wunner)

  Power control:

   - Add a struct pci_ops.assert_perst() function pointer to
     assert/deassert PCIe PERST# and implement it for the qcom driver
     (Krishna Chaitanya Chundru)

   - Add DT binding and pwrctrl driver for the Toshiba TC9563 PCIe
     switch, which must be held in reset after poweron so the pwrctrl
     driver can configure the switch via I2C before bringing up the
     links (Krishna Chaitanya Chundru)

  Endpoint framework:

   - Convert the endpoint doorbell test to use a threaded IRQ to fix a
     'sleeping while atomic' issue (Bhanu Seshu Kumar Valluri)

   - Add endpoint VNTB MSI doorbell support to reduce latency between
     host and endpoint (Frank Li)

  New native PCIe controller drivers:

   - Add CIX Sky1 host controller DT binding and driver (Hans Zhang)

   - Add NXP S32G host controller DT binding and driver (Vincent
     Guittot)

   - Add Renesas RZ/G3S host controller DT binding and driver (Claudiu
     Beznea)

   - Add SpacemiT K1 host controller DT binding and driver (Alex Elder)

  Amlogic Meson PCIe controller driver:

   - Update DT binding to name DBI region 'dbi', not 'elbi', and update
     driver to support both (Manivannan Sadhasivam)

  Apple PCIe controller driver:

   - Move struct pci_host_bridge allocation from pci_host_common_init()
     to callers, which significantly simplifies pcie-apple (Marc
     Zyngier)

  Broadcom STB PCIe controller driver:

   - Disable advertising ASPM L0s support correctly (Jim Quinlan)

   - Add a panic/die handler to print diagnostic info in case PCIe
     caused an unrecoverable abort (Jim Quinlan)

  Cadence PCIe controller driver:

   - Add module support for Cadence platform host and endpoint
     controller driver (Manikandan K Pillai)

   - Split headers into 'legacy' (LGA) and 'high perf' (HPA) to prepare
     for new CIX Sky1 driver (Manikandan K Pillai)

  MediaTek PCIe controller driver:

   - Convert DT binding to YAML schema (Christian Marangi)

   - Add Airoha AN7583 DT compatible and driver support (Christian
     Marangi)

  Qualcomm PCIe controller driver:

   - Add Qualcomm Kaanapali to SM8550 DT binding (Qiang Yu)

   - Add required 'power-domains' and 'resets' to qcom sa8775p, sc7280,
     sc8280xp, sm8150, sm8250, sm8350, sm8450, sm8550, x1e80100 DT
     schemas (Krzysztof Kozlowski)

   - Look up OPP using both frequency and data rate (not just frequency)
     so RPMh votes can account for both (Krishna Chaitanya Chundru)

  Rockchip DesignWare PCIe controller driver:

   - Add Rockchip RK3528 compatible strings in DT binding (Yao Zi)

  STMicroelectronics STM32MP25 PCIe controller driver:

   - Fix a race between link training and endpoint register
     initialization (Christian Bruel)

   - Align endpoint allocations to match the ATU requirements (Christian
     Bruel)

  Synopsys DesignWare PCIe controller driver:

   - Clear L1 PM Substate Capability 'Supported' bits unless glue driver
     says it's supported, which prevents users from enabling non-working
     L1SS. Currently only qcom and tegra194 support L1SS (Bjorn Helgaas)

   - Remove now-superfluous L1SS disable code from tegra194 (Bjorn
     Helgaas)

   - Configure L1SS support in dw-rockchip when DT says
     'supports-clkreq' (Shawn Lin)

  TI Keystone PCIe controller driver:

   - Fail the probe instead of silently succeeding if ks_pcie_of_data
     didn't specify Root Complex or Endpoint mode (Siddharth Vadapalli)

   - Make keystone buildable as a loadable module, except on ARM32 where
     hook_fault_code() is __init (Siddharth Vadapalli)"

* tag 'pci-v6.19-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: (100 commits)
  MAINTAINERS: Add Manivannan Sadhasivam as PCI/pwrctrl maintainer
  MAINTAINERS: Add CIX Sky1 PCIe controller driver maintainer
  PCI: sky1: Add PCIe host support for CIX Sky1
  dt-bindings: PCI: Add CIX Sky1 PCIe Root Complex bindings
  PCI: cadence: Add support for High Perf Architecture (HPA) controller
  MAINTAINERS: Add NXP S32G PCIe controller driver maintainer
  PCI: s32g: Add NXP S32G PCIe controller driver (RC)
  PCI: dwc: Add register and bitfield definitions
  dt-bindings: PCI: s32g: Add NXP S32G PCIe controller
  PCI: Add Renesas RZ/G3S host controller driver
  PCI: host-generic: Move bridge allocation outside of pci_host_common_init()
  dt-bindings: PCI: Add Renesas RZ/G3S PCIe controller binding
  PCI: Validate pci_rebar_size_supported() input
  Documentation: PCI: Amend error recovery doc with pci_save_state() rules
  treewide: Drop pci_save_state() after pci_restore_state()
  PCI/ERR: Ensure error recoverability at all times
  PCI/PM: Stop needlessly clearing state_saved on enumeration and thaw
  PCI/PM: Reinstate clearing state_saved in legacy and !PM codepaths
  PCI: dw-rockchip: Configure L1SS support
  PCI: tegra194: Remove unnecessary L1SS disable code
  ...