1 files changed, 67 insertions, 0 deletions
diff --git a/debian/patches-rt/0092-printk-ringbuffer-Cleanup-reader-terminology.patch b/debian/patches-rt/0092-printk-ringbuffer-Cleanup-reader-terminology.patch
new file mode 100644
index 0000000000..31c6312c46
--- /dev/null
+++ b/debian/patches-rt/0092-printk-ringbuffer-Cleanup-reader-terminology.patch
@@ -0,0 +1,67 @@
+From: John Ogness <john.ogness@linutronix.de>
+Date: Mon, 6 Nov 2023 15:01:58 +0000
+Subject: [PATCH 092/134] printk: ringbuffer: Cleanup reader terminology
+Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6.7-rt18.tar.xz
+
+With the lockless ringbuffer, it is allowed that multiple
+CPUs/contexts write simultaneously into the buffer. This creates
+an ambiguity as some writers will finalize sooner.
+
+The documentation for the prb_read functions is not clear as it
+refers to "not yet written" and "no data available". Clarify the
+return values and language to be in terms of the reader: records
+available for reading.
+
+Signed-off-by: John Ogness <john.ogness@linutronix.de>
+Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+---
+ kernel/printk/printk_ringbuffer.c |   16 +++++++++-------
+ 1 file changed, 9 insertions(+), 7 deletions(-)
+
+--- a/kernel/printk/printk_ringbuffer.c
++++ b/kernel/printk/printk_ringbuffer.c
+@@ -1987,11 +1987,13 @@ u64 prb_first_seq(struct printk_ringbuff
+ }
+ 
+ /*
+- * Non-blocking read of a record. Updates @seq to the last finalized record
+- * (which may have no data available).
++ * Non-blocking read of a record.
+  *
+- * See the description of prb_read_valid() and prb_read_valid_info()
+- * for details.
++ * On success @seq is updated to the record that was read and (if provided)
++ * @r and @line_count will contain the read/calculated data.
++ *
++ * On failure @seq is updated to a record that is not yet available to the
++ * reader, but it will be the next record available to the reader.
+  */
+ static bool _prb_read_valid(struct printk_ringbuffer *rb, u64 *seq,
+ 			    struct printk_record *r, unsigned int *line_count)
+@@ -2010,7 +2012,7 @@ static bool _prb_read_valid(struct print
+ 			*seq = tail_seq;
+ 
+ 		} else if (err == -ENOENT) {
+-			/* Record exists, but no data available. Skip. */
++			/* Record exists, but the data was lost. Skip. */
+ 			(*seq)++;
+ 
+ 		} else {
+@@ -2043,7 +2045,7 @@ static bool _prb_read_valid(struct print
+  * On success, the reader must check r->info.seq to see which record was
+  * actually read. This allows the reader to detect dropped records.
+  *
+- * Failure means @seq refers to a not yet written record.
++ * Failure means @seq refers to a record not yet available to the reader.
+  */
+ bool prb_read_valid(struct printk_ringbuffer *rb, u64 seq,
+ 		    struct printk_record *r)
+@@ -2073,7 +2075,7 @@ bool prb_read_valid(struct printk_ringbu
+  * On success, the reader must check info->seq to see which record meta data
+  * was actually read. This allows the reader to detect dropped records.
+  *
+- * Failure means @seq refers to a not yet written record.
++ * Failure means @seq refers to a record not yet available to the reader.
+  */
+ bool prb_read_valid_info(struct printk_ringbuffer *rb, u64 seq,
+ 			 struct printk_info *info, unsigned int *line_count)