From c5bb4969d45d74a2076fcd77a5ca69173dcb0beb Mon Sep 17 00:00:00 2001 From: John Ogness Date: Wed, 22 Nov 2023 11:23:43 +0000 Subject: [PATCH 125/196] printk: Consider nbcon boot consoles on seq init If a non-boot console is registering and boot consoles exist, the consoles are flushed before being unregistered. This allows the non-boot console to continue where the boot console left off. If for whatever reason flushing fails, the lowest seq found from any of the enabled boot consoles is used. Until now con->seq was checked. However, if it is an nbcon boot console, the function nbcon_seq_read() must be used to read seq because con->seq is always 0. Check if it is an nbcon boot console and if so call nbcon_seq_read() to read seq. Signed-off-by: John Ogness Signed-off-by: Sebastian Andrzej Siewior --- kernel/printk/printk.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 15cc485109a5..87d3510e3e45 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -3392,11 +3392,20 @@ static void console_init_seq(struct console *newcon, bool bootcon_registered) newcon->seq = prb_next_seq(prb); for_each_console(con) { - if ((con->flags & CON_BOOT) && - (con->flags & CON_ENABLED) && - con->seq < newcon->seq) { - newcon->seq = con->seq; + u64 seq; + + if (!((con->flags & CON_BOOT) && + (con->flags & CON_ENABLED))) { + continue; } + + if (con->flags & CON_NBCON) + seq = nbcon_seq_read(con); + else + seq = con->seq; + + if (seq < newcon->seq) + newcon->seq = seq; } } -- 2.43.2