diff options
Diffstat (limited to 'debian/patches-rt/0006-printk-nbcon-Add-callbacks-to-synchronize-with-drive.patch')
| -rw-r--r-- | debian/patches-rt/0006-printk-nbcon-Add-callbacks-to-synchronize-with-drive.patch | 25 |
1 files changed, 13 insertions, 12 deletions
diff --git a/debian/patches-rt/0006-printk-nbcon-Add-callbacks-to-synchronize-with-drive.patch b/debian/patches-rt/0006-printk-nbcon-Add-callbacks-to-synchronize-with-drive.patch index 0323d580c4..ef850cfd27 100644 --- a/debian/patches-rt/0006-printk-nbcon-Add-callbacks-to-synchronize-with-drive.patch +++ b/debian/patches-rt/0006-printk-nbcon-Add-callbacks-to-synchronize-with-drive.patch @@ -1,7 +1,7 @@ From: John Ogness <john.ogness@linutronix.de> Date: Mon, 18 Mar 2024 10:11:56 +0000 -Subject: [PATCH 06/46] printk: nbcon: Add callbacks to synchronize with driver -Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.9/older/patches-6.9-rt5.tar.xz +Subject: [PATCH 06/48] printk: nbcon: Add callbacks to synchronize with driver +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.10/older/patches-6.10.2-rt14.tar.xz Console drivers typically must deal with access to the hardware via user input/output (such as an interactive login shell) and @@ -12,19 +12,20 @@ serial consoles). Until now, usage of this driver-specific locking has been hidden from the printk-subsystem and implemented within the various -console callbacks. However, for nbcon consoles, it is necessary -that the printk-subsystem uses the driver-specific locking so -that nbcon console ownership can be acquired _after_ the -driver-specific locking has succeeded. This allows for lock -contention to exist on the more context-friendly driver-specific -locking rather than nbcon console ownership (for non-emergency -and non-panic cases). +console callbacks. However, nbcon consoles would need to use it +even in the generic code. -Require nbcon consoles to implement two new callbacks -(device_lock(), device_unlock()) that will use whatever -synchronization mechanism the driver is using for itself. +Add device_lock() and device_unlock() callback which will need +to get implemented by nbcon consoles. + +The callbacks will use whatever synchronization mechanism the +driver is using for itself. The minimum requirement is to +prevent CPU migration. It would allow a context friendly +acquiring of nbcon console ownership in non-emergency and +non-panic context. Signed-off-by: John Ogness <john.ogness@linutronix.de> +Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> --- include/linux/console.h | 43 +++++++++++++++++++++++++++++++++++++++++++ |