From: John Ogness <john.ogness@linutronix.de>
To: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>,
Steven Rostedt <rostedt@goodmis.org>,
Thomas Gleixner <tglx@linutronix.de>,
linux-kernel@vger.kernel.org,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: [PATCH printk v6 03/30] printk: nbcon: Remove return value for write_atomic()
Date: Mon, 27 May 2024 08:43:22 +0206 [thread overview]
Message-ID: <20240527063749.391035-4-john.ogness@linutronix.de> (raw)
In-Reply-To: <20240527063749.391035-1-john.ogness@linutronix.de>
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 <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
---
include/linux/console.h | 2 +-
kernel/printk/nbcon.c | 15 +++++++--------
2 files changed, 8 insertions(+), 9 deletions(-)
diff --git a/include/linux/console.h b/include/linux/console.h
index 779d388af8a0..54b98e4f0544 100644
--- 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;
diff --git a/kernel/printk/nbcon.c b/kernel/printk/nbcon.c
index de260531b0da..dd7c3180b335 100644
--- a/kernel/printk/nbcon.c
+++ b/kernel/printk/nbcon.c
@@ -849,7 +849,6 @@ static bool nbcon_emit_next_record(struct nbcon_write_context *wctxt)
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(struct nbcon_write_context *wctxt)
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
--
2.39.2
next prev parent reply other threads:[~2024-05-27 6:38 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-27 6:37 [PATCH printk v6 00/30] wire up write_atomic() printing John Ogness
2024-05-27 6:37 ` [PATCH printk v6 01/30] printk: Add notation to console_srcu locking John Ogness
2024-05-27 6:37 ` [PATCH printk v6 02/30] printk: Properly deal with nbcon consoles on seq init John Ogness
2024-05-27 6:37 ` John Ogness [this message]
2024-05-27 6:37 ` [PATCH printk v6 04/30] printk: Check printk_deferred_enter()/_exit() usage John Ogness
2024-05-27 6:37 ` [PATCH printk v6 05/30] printk: nbcon: Add detailed doc for write_atomic() John Ogness
2024-05-27 6:37 ` [PATCH printk v6 06/30] printk: nbcon: Add callbacks to synchronize with driver John Ogness
2024-05-27 6:37 ` [PATCH printk v6 07/30] printk: nbcon: Use driver synchronization while (un)registering John Ogness
2024-05-27 6:37 ` [PATCH printk v6 08/30] serial: core: Provide low-level functions to lock port John Ogness
2024-05-27 6:37 ` [PATCH printk v6 09/30] serial: core: Introduce wrapper to set @uart_port->cons John Ogness
2024-05-27 6:37 ` [PATCH printk v6 10/30] console: Improve console_srcu_read_flags() comments John Ogness
2024-05-27 6:37 ` [PATCH printk v6 11/30] nbcon: Add API to acquire context for non-printing operations John Ogness
2024-05-27 6:37 ` [PATCH printk v6 12/30] serial: core: Implement processing in port->lock wrapper John Ogness
2024-05-27 6:37 ` [PATCH printk v6 13/30] printk: nbcon: Do not rely on proxy headers John Ogness
2024-05-27 6:37 ` [PATCH printk v6 14/30] printk: nbcon: Fix kerneldoc for enums John Ogness
2024-05-27 6:37 ` [PATCH printk v6 15/30] printk: Make console_is_usable() available to nbcon John Ogness
2024-05-27 6:37 ` [PATCH printk v6 16/30] printk: Let console_is_usable() handle nbcon John Ogness
2024-05-27 6:37 ` [PATCH printk v6 17/30] printk: Add @flags argument for console_is_usable() John Ogness
2024-05-27 6:37 ` [PATCH printk v6 18/30] printk: nbcon: Add helper to assign priority based on CPU state John Ogness
2024-05-27 6:37 ` [PATCH printk v6 19/30] printk: nbcon: Provide function to flush using write_atomic() John Ogness
2024-05-28 9:30 ` Petr Mladek
2024-05-27 6:37 ` [PATCH printk v6 20/30] printk: Track registered boot consoles John Ogness
2024-05-27 6:37 ` [PATCH printk v6 21/30] printk: nbcon: Use nbcon consoles in console_flush_all() John Ogness
2024-05-27 6:37 ` [PATCH printk v6 22/30] printk: nbcon: Add unsafe flushing on panic John Ogness
2024-05-27 6:37 ` [PATCH printk v6 23/30] printk: Avoid console_lock dance if no legacy or boot consoles John Ogness
2024-05-27 6:37 ` [PATCH printk v6 24/30] printk: Track nbcon consoles John Ogness
2024-05-27 6:37 ` [PATCH printk v6 25/30] printk: Coordinate direct printing in panic John Ogness
2024-05-27 6:37 ` [PATCH printk v6 26/30] printk: nbcon: Implement emergency sections John Ogness
2024-05-28 9:57 ` Petr Mladek
2024-05-27 6:37 ` [PATCH printk v6 27/30] panic: Mark emergency section in warn John Ogness
2024-05-27 6:37 ` [PATCH printk v6 28/30] panic: Mark emergency section in oops John Ogness
2024-05-27 6:37 ` [PATCH printk v6 29/30] rcu: Mark emergency sections in rcu stalls John Ogness
2024-05-28 10:04 ` Petr Mladek
2024-05-27 6:37 ` [PATCH printk v6 30/30] lockdep: Mark emergency sections in lockdep splats John Ogness
2024-05-28 10:10 ` [PATCH printk v6 00/30] wire up write_atomic() printing Petr Mladek
2024-05-28 13:35 ` Petr Mladek
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