From: John Ogness Date: Fri, 20 Oct 2023 09:52:59 +0000 Subject: [PATCH 08/48] printk: nbcon: Remove return value for write_atomic() Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.8/older/patches-6.8.2-rt11.tar.xz The return value of write_atomic() does not provide any useful information. On the contrary, it makes things more complicated for the caller to appropriately deal with the information. Change write_atomic() to not have a return value. If the message did not get printed due to loss of ownership, the caller will notice this on its own. If ownership was not lost, it will be assumed that the driver successfully printed the message and the sequence number for that console will be incremented. Signed-off-by: John Ogness Signed-off-by: Sebastian Andrzej Siewior --- include/linux/console.h | 2 +- kernel/printk/nbcon.c | 15 +++++++-------- 2 files changed, 8 insertions(+), 9 deletions(-) --- a/include/linux/console.h +++ b/include/linux/console.h @@ -327,7 +327,7 @@ struct console { struct hlist_node node; /* nbcon console specific members */ - bool (*write_atomic)(struct console *con, + void (*write_atomic)(struct console *con, struct nbcon_write_context *wctxt); atomic_t __private nbcon_state; atomic_long_t __private nbcon_seq; --- a/kernel/printk/nbcon.c +++ b/kernel/printk/nbcon.c @@ -849,7 +849,6 @@ static bool nbcon_emit_next_record(struc unsigned long con_dropped; struct nbcon_state cur; unsigned long dropped; - bool done; /* * The printk buffers are filled within an unsafe section. This @@ -889,16 +888,16 @@ static bool nbcon_emit_next_record(struc wctxt->unsafe_takeover = cur.unsafe_takeover; if (con->write_atomic) { - done = con->write_atomic(con, wctxt); + con->write_atomic(con, wctxt); } else { - nbcon_context_release(ctxt); + /* + * This function should never be called for legacy consoles. + * Handle it as if ownership was lost and try to continue. + */ WARN_ON_ONCE(1); - done = false; - } - - /* If not done, the emit was aborted. */ - if (!done) + nbcon_context_release(ctxt); return false; + } /* * Since any dropped message was successfully output, reset the