Commit 4d38b88fd17e for kernel

commit 4d38b88fd17e9989429e65420bf3c33ca53b2085
Merge: 4a4e0199378f 5cae92e62230
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Wed Dec 3 12:42:36 2025 -0800

    Merge tag 'printk-for-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

    Pull printk updates from Petr Mladek:

     - Allow creaing nbcon console drivers with an unsafe write_atomic()
       callback that can only be called by the final nbcon_atomic_flush_unsafe().
       Otherwise, the driver would rely on the kthread.

       It is going to be used as the-best-effort approach for an
       experimental nbcon netconsole driver, see

         https://lore.kernel.org/r/20251121-nbcon-v1-2-503d17b2b4af@debian.org

       Note that a safe .write_atomic() callback is supposed to work in NMI
       context. But some networking drivers are not safe even in IRQ
       context:

         https://lore.kernel.org/r/oc46gdpmmlly5o44obvmoatfqo5bhpgv7pabpvb6sjuqioymcg@gjsma3ghoz35

       In an ideal world, all networking drivers would be fixed first and
       the atomic flush would be blocked only in NMI context. But it brings
       the question how reliable networking drivers are when the system is
       in a bad state. They might block flushing more reliable serial
       consoles which are more suitable for serious debugging anyway.

     - Allow to use the last 4 bytes of the printk ring buffer.

     - Prevent queuing IRQ work and block printk kthreads when consoles are
       suspended. Otherwise, they create non-necessary churn or even block
       the suspend.

     - Release console_lock() between each record in the kthread used for
       legacy consoles on RT. It might significantly speed up the boot.

     - Release nbcon context between each record in the atomic flush. It
       prevents stalls of the related printk kthread after it has lost the
       ownership in the middle of a record

     - Add support for NBCON consoles into KDB

     - Add %ptsP modifier for printing struct timespec64 and use it where
       possible

     - Misc code clean up

    * tag 'printk-for-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: (48 commits)
      printk: Use console_is_usable on console_unblank
      arch: um: kmsg_dump: Use console_is_usable
      drivers: serial: kgdboc: Drop checks for CON_ENABLED and CON_BOOT
      lib/vsprintf: Unify FORMAT_STATE_NUM handlers
      printk: Avoid irq_work for printk_deferred() on suspend
      printk: Avoid scheduling irq_work on suspend
      printk: Allow printk_trigger_flush() to flush all types
      tracing: Switch to use %ptSp
      scsi: snic: Switch to use %ptSp
      scsi: fnic: Switch to use %ptSp
      s390/dasd: Switch to use %ptSp
      ptp: ocp: Switch to use %ptSp
      pps: Switch to use %ptSp
      PCI: epf-test: Switch to use %ptSp
      net: dsa: sja1105: Switch to use %ptSp
      mmc: mmc_test: Switch to use %ptSp
      media: av7110: Switch to use %ptSp
      ipmi: Switch to use %ptSp
      igb: Switch to use %ptSp
      e1000e: Switch to use %ptSp
      ...