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authorTakashi Iwai <tiwai@suse.de>2021-08-30 14:57:03 +0200
committerTakashi Iwai <tiwai@suse.de>2021-08-30 14:57:03 +0200
commita8729efbbb847f6ea9b06e73491ec8ddb560465e (patch)
treec2e172452158457ab238080405060110934ad9d1 /kernel/trace/ring_buffer.c
parentf7b82b12626e10a2f5332b699cc79819ac8decc7 (diff)
parent38b7673000949ca784fcb8a9feb70d2a802befa6 (diff)
downloadlinux-a8729efbbb847f6ea9b06e73491ec8ddb560465e.tar.gz
linux-a8729efbbb847f6ea9b06e73491ec8ddb560465e.zip
Merge tag 'asoc-v5.15' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus
ASoC: Updates for v5.15 Quite a quiet release this time, mostly a combination of cleanups and a good set of new drivers. - Lots of cleanups and improvements to the Intel drivers, including some new systems support. - New support for AMD Vangoh, CUI CMM-4030D-261, Mediatek Mt8195, Renesas RZ/G2L Mediatek Mt8195, RealTek RT101P, Renesas RZ/G2L,, Rockchip RK3568 S/PDIF.
Diffstat (limited to 'kernel/trace/ring_buffer.c')
-rw-r--r--kernel/trace/ring_buffer.c28
1 files changed, 24 insertions, 4 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index d1463eac11a3..e592d1df6f88 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -3880,10 +3880,30 @@ static bool rb_per_cpu_empty(struct ring_buffer_per_cpu *cpu_buffer)
if (unlikely(!head))
return true;
- return reader->read == rb_page_commit(reader) &&
- (commit == reader ||
- (commit == head &&
- head->read == rb_page_commit(commit)));
+ /* Reader should exhaust content in reader page */
+ if (reader->read != rb_page_commit(reader))
+ return false;
+
+ /*
+ * If writers are committing on the reader page, knowing all
+ * committed content has been read, the ring buffer is empty.
+ */
+ if (commit == reader)
+ return true;
+
+ /*
+ * If writers are committing on a page other than reader page
+ * and head page, there should always be content to read.
+ */
+ if (commit != head)
+ return false;
+
+ /*
+ * Writers are committing on the head page, we just need
+ * to care about there're committed data, and the reader will
+ * swap reader page with head page when it is to read data.
+ */
+ return rb_page_commit(commit) == 0;
}
/**