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authorJohn Ogness <john.ogness@linutronix.de>2024-09-04 14:11:24 +0206
committerPetr Mladek <pmladek@suse.com>2024-09-04 15:56:32 +0200
commitfb9fabf3d86216961d1103ecbc33e98d5f6c48f5 (patch)
tree055350c243e9ec4761c8171fbcd50e7353b2fddc /kernel/printk/printk_ringbuffer.h
parent6cb58cfebb293286f5ce8f6fba3e29122308e9e0 (diff)
printk: nbcon: Init @nbcon_seq to highest possible
When initializing an nbcon console, have nbcon_alloc() set @nbcon_seq to the highest possible sequence number. For all practical purposes, this will guarantee that the console will have nothing to print until later when @nbcon_seq is set to the proper initial printing value. This will be particularly important once kthread printing is introduced because nbcon_alloc() can create/start the kthread before the desired initial sequence number is known. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20240904120536.115780-6-john.ogness@linutronix.de Signed-off-by: Petr Mladek <pmladek@suse.com>
Diffstat (limited to 'kernel/printk/printk_ringbuffer.h')
-rw-r--r--kernel/printk/printk_ringbuffer.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/printk/printk_ringbuffer.h b/kernel/printk/printk_ringbuffer.h
index 8de6c495cf2b..4ef81349d9fb 100644
--- a/kernel/printk/printk_ringbuffer.h
+++ b/kernel/printk/printk_ringbuffer.h
@@ -404,10 +404,12 @@ u64 prb_next_reserve_seq(struct printk_ringbuffer *rb);
#define __u64seq_to_ulseq(u64seq) (u64seq)
#define __ulseq_to_u64seq(rb, ulseq) (ulseq)
+#define ULSEQ_MAX(rb) (-1)
#else /* CONFIG_64BIT */
#define __u64seq_to_ulseq(u64seq) ((u32)u64seq)
+#define ULSEQ_MAX(rb) __u64seq_to_ulseq(prb_first_seq(rb) + 0x80000000UL)
static inline u64 __ulseq_to_u64seq(struct printk_ringbuffer *rb, u32 ulseq)
{