From: Saravana Kannan <saravanak@google.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Saravana Kannan <saravanak@google.com>
Cc: kernel-team@android.com,
"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH v1] driver core: Fix handling of SYNC_STATE_ONLY + STATELESS device links
Date: Tue, 19 May 2020 21:36:26 -0700 [thread overview]
Message-ID: <20200520043626.181820-1-saravanak@google.com> (raw)
Commit 21c27f06587d ("driver core: Fix SYNC_STATE_ONLY device link
implementation") didn't completely fix STATELESS + SYNC_STATE_ONLY
handling.
What looks like an optimization in that commit is actually a bug that
causes an if condition to always take the else path. This prevents
reordering of devices in the dpm_list when a DL_FLAG_STATELESS device
link is create on top of an existing DL_FLAG_SYNC_STATE_ONLY device
link.
Fixes: 21c27f06587d ("driver core: Fix SYNC_STATE_ONLY device link implementation")
Signed-off-by: Saravana Kannan <saravanak@google.com>
---
Sigh... device links are tricky and hard! Sorry about the endless fixes :(
Also, how was this not caught by the compiler as a warning?
-Saravana
drivers/base/core.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 83a3e0b62ce3..dfd4e94ef790 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -543,12 +543,14 @@ struct device_link *device_link_add(struct device *consumer,
if (flags & DL_FLAG_STATELESS) {
kref_get(&link->kref);
- link->flags |= DL_FLAG_STATELESS;
if (link->flags & DL_FLAG_SYNC_STATE_ONLY &&
- !(link->flags & DL_FLAG_STATELESS))
+ !(link->flags & DL_FLAG_STATELESS)) {
+ link->flags |= DL_FLAG_STATELESS;
goto reorder;
- else
+ } else {
+ link->flags |= DL_FLAG_STATELESS;
goto out;
+ }
}
/*
--
2.26.2.761.g0e0b3e54be-goog
next reply other threads:[~2020-05-20 4:36 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-20 4:36 Saravana Kannan [this message]
2020-05-20 4:38 ` [PATCH v1] driver core: Fix handling of SYNC_STATE_ONLY + STATELESS device links Saravana Kannan
2020-05-20 9:13 ` Rafael J. Wysocki
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