pm24.git/drivers/tty/serial, branch cpufreq-rust

Merge tag 'driver-core-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2025-01-28T20:25:12Z

Pull driver core and debugfs updates from Greg KH: "Here is the big set of driver core and debugfs updates for 6.14-rc1. Included in here is a bunch of driver core, PCI, OF, and platform rust bindings (all acked by the different subsystem maintainers), hence the merge conflict with the rust tree, and some driver core api updates to mark things as const, which will also require some fixups due to new stuff coming in through other trees in this merge window. There are also a bunch of debugfs updates from Al, and there is at least one user that does have a regression with these, but Al is working on tracking down the fix for it. In my use (and everyone else's linux-next use), it does not seem like a big issue at the moment. Here's a short list of the things in here: - driver core rust bindings for PCI, platform, OF, and some i/o functions. We are almost at the "write a real driver in rust" stage now, depending on what you want to do. - misc device rust bindings and a sample driver to show how to use them - debugfs cleanups in the fs as well as the users of the fs api for places where drivers got it wrong or were unnecessarily doing things in complex ways. - driver core const work, making more of the api take const * for different parameters to make the rust bindings easier overall. - other small fixes and updates All of these have been in linux-next with all of the aforementioned merge conflicts, and the one debugfs issue, which looks to be resolved "soon"" * tag 'driver-core-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (95 commits) rust: device: Use as_char_ptr() to avoid explicit cast rust: device: Replace CString with CStr in property_present() devcoredump: Constify 'struct bin_attribute' devcoredump: Define 'struct bin_attribute' through macro rust: device: Add property_present() saner replacement for debugfs_rename() orangefs-debugfs: don't mess with ->d_name octeontx2: don't mess with ->d_parent or ->d_parent->d_name arm_scmi: don't mess with ->d_parent->d_name slub: don't mess with ->d_name sof-client-ipc-flood-test: don't mess with ->d_name qat: don't mess with ->d_name xhci: don't mess with ->d_iname mtu3: don't mess wiht ->d_iname greybus/camera - stop messing with ->d_iname mediatek: stop messing with ->d_iname netdevsim: don't embed file_operations into your structs b43legacy: make use of debugfs_get_aux() b43: stop embedding struct file_operations into their objects carl9170: stop embedding file_operations into their objects ...

Revert "serial: 8250: Switch to nbcon console"

2025-01-22T09:35:56Z

This reverts commit b63e6f60eab45b16a1bf734fef9035a4c4187cd5. kernel test robot has found problems with this commit so revert it for now. Link: https://lore.kernel.org/r/202501221029.fb0d574d-lkp@intel.com Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-lkp/202501221029.fb0d574d-lkp@intel.com Cc: John Ogness Cc: Petr Mladek Signed-off-by: Greg Kroah-Hartman

Revert "serial: 8250: Revert "drop lockdep annotation from serial8250_clear_IER()""

2025-01-22T09:34:25Z

This reverts commit 422c9727b07f9f86e2ec11c56622e566221591cc. kernel test robot has found problems with this commit so revert it for now. Link: https://lore.kernel.org/r/202501221029.fb0d574d-lkp@intel.com Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-lkp/202501221029.fb0d574d-lkp@intel.com Cc: John Ogness Cc: Petr Mladek Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Increment the runtime usage counter for the earlycon device

2025-01-17T11:54:37Z

In the sh-sci driver, serial ports are mapped to the sci_ports[] array, with earlycon mapped at index zero. The uart_add_one_port() function eventually calls __device_attach(), which, in turn, calls pm_request_idle(). The identified code path is as follows: uart_add_one_port() -> serial_ctrl_register_port() -> serial_core_register_port() -> serial_core_port_device_add() -> serial_base_port_add() -> device_add() -> bus_probe_device() -> device_initial_probe() -> __device_attach() -> // ... if (dev->p->dead) { // ... } else if (dev->driver) { // ... } else { // ... pm_request_idle(dev); // ... } The earlycon device clocks are enabled by the bootloader. However, the pm_request_idle() call in __device_attach() disables the SCI port clocks while earlycon is still active. The earlycon write function, serial_console_write(), calls sci_poll_put_char() via serial_console_putchar(). If the SCI port clocks are disabled, writing to earlycon may sometimes cause the SR.TDFE bit to remain unset indefinitely, causing the while loop in sci_poll_put_char() to never exit. On single-core SoCs, this can result in the system being blocked during boot when this issue occurs. To resolve this, increment the runtime PM usage counter for the earlycon SCI device before registering the UART port. Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Cc: stable@vger.kernel.org Signed-off-by: Claudiu Beznea Link: https://lore.kernel.org/r/20250116182249.3828577-6-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Clean sci_ports[0] after at earlycon exit

2025-01-17T11:54:37Z

The early_console_setup() function initializes sci_ports[0].port with an object of type struct uart_port obtained from the struct earlycon_device passed as an argument to early_console_setup(). Later, during serial port probing, the serial port used as earlycon (e.g., port A) might be remapped to a different position in the sci_ports[] array, and a different serial port (e.g., port B) might be assigned to slot 0. For example: sci_ports[0] = port B sci_ports[X] = port A In this scenario, the new port mapped at index zero (port B) retains the data associated with the earlycon configuration. Consequently, after the Linux boot process, any access to the serial port now mapped to sci_ports[0] (port B) will block the original earlycon port (port A). To address this, introduce an early_console_exit() function to clean up sci_ports[0] when earlycon is exited. To prevent the cleanup of sci_ports[0] while the serial device is still being used by earlycon, introduce the struct sci_port::probing flag and account for it in early_console_exit(). Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Cc: stable@vger.kernel.org Signed-off-by: Claudiu Beznea Link: https://lore.kernel.org/r/20250116182249.3828577-5-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Do not probe the serial port if its slot in sci_ports[] is in use

2025-01-17T11:54:37Z

In the sh-sci driver, sci_ports[0] is used by earlycon. If the earlycon is still active when sci_probe() is called and the new serial port is supposed to map to sci_ports[0], return -EBUSY to prevent breaking the earlycon. This situation should occurs in debug scenarios, and users should be aware of the potential conflict. Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Cc: stable@vger.kernel.org Signed-off-by: Claudiu Beznea Link: https://lore.kernel.org/r/20250116182249.3828577-4-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Move runtime PM enable to sci_probe_single()

2025-01-17T11:54:36Z

Relocate the runtime PM enable operation to sci_probe_single(). This change prepares the codebase for upcoming fixes. While at it, replace the existing logic with a direct call to devm_pm_runtime_enable() and remove sci_cleanup_single(). The devm_pm_runtime_enable() function automatically handles disabling runtime PM during driver removal. Reviewed-by: Geert Uytterhoeven Signed-off-by: Claudiu Beznea Link: https://lore.kernel.org/r/20250116182249.3828577-3-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Drop __initdata macro for port_cfg

2025-01-17T11:54:36Z

The port_cfg object is used by serial_console_write(), which serves as the write function for the earlycon device. Marking port_cfg as __initdata causes it to be freed after kernel initialization, resulting in earlycon becoming unavailable thereafter. Remove the __initdata macro from port_cfg to resolve this issue. Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Cc: stable@vger.kernel.org Reviewed-by: Geert Uytterhoeven Signed-off-by: Claudiu Beznea Fixes: 0b0cced19ab15c9e ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Link: https://lore.kernel.org/r/20250116182249.3828577-2-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman

serial: kgdb_nmi: Remove unused knock code

2025-01-17T11:52:27Z

kgdb_nmi_poll_knock() has been unused since it was added in 2013 in commit 0c57dfcc6c1d ("tty/serial: Add kgdb_nmi driver") Remove it, the static helpers, and module parameters it used. (The comment explaining why it might be used sounds sensible, but it's never been wired up, perhaps it's worth doing somewhere?) Signed-off-by: Dr. David Alan Gilbert Link: https://lore.kernel.org/r/20250112135759.105541-1-linux@treblig.org Signed-off-by: Greg Kroah-Hartman

tty: xilinx_uartps: split sysrq handling

2025-01-13T05:46:50Z

lockdep detects the following circular locking dependency: CPU 0 CPU 1 ========================== ============================ cdns_uart_isr() printk() uart_port_lock(port) console_lock() cdns_uart_console_write() if (!port->sysrq) uart_port_lock(port) uart_handle_break() port->sysrq = ... uart_handle_sysrq_char() printk() console_lock() The fixed commit attempts to avoid this situation by only taking the port lock in cdns_uart_console_write if port->sysrq unset. However, if (as shown above) cdns_uart_console_write runs before port->sysrq is set, then it will try to take the port lock anyway. This may result in a deadlock. Fix this by splitting sysrq handling into two parts. We use the prepare helper under the port lock and defer handling until we release the lock. Fixes: 74ea66d4ca06 ("tty: xuartps: Improve sysrq handling") Signed-off-by: Sean Anderson Cc: stable@vger.kernel.org # c980248179d: serial: xilinx_uartps: Use port lock wrappers Acked-by: John Ogness Link: https://lore.kernel.org/r/20250110213822.2107462-1-sean.anderson@linux.dev Signed-off-by: Greg Kroah-Hartman