From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-kernel@vger.kernel.org,
Saravana Kannan <saravanak@google.com>,
linux-acpi@vger.kernel.org,
"Rafael J. Wysocki" <rafael@kernel.org>,
Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Ferry Toth <fntoth@gmail.com>
Subject: [PATCH v1 2/2] device property: Don't clear secondary pointer for shared primary firmware node
Date: Thu, 22 Oct 2020 21:41:00 +0300 [thread overview]
Message-ID: <20201022184100.71659-2-andriy.shevchenko@linux.intel.com> (raw)
In-Reply-To: <20201022184100.71659-1-andriy.shevchenko@linux.intel.com>
It appears that firmware nodes can be shared between devices. In such case
when a (child) device is about to be deleted, its firmware node may be shared
and ACPI_COMPANION_SET(..., NULL) call for it breaks the secondary link
of the shared primary firmware node.
In order to prevent that, check, if the device has a parent and parent's
firmware node is shared with its child, and avoid crashing the link.
Fixes: c15e1bdda436 ("device property: Fix the secondary firmware node handling in set_primary_fwnode()")
Reported-by: Ferry Toth <fntoth@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
drivers/base/core.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 41feab679fa1..78114ddac755 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -4264,6 +4264,7 @@ static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
*/
void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
{
+ struct device *parent = dev->parent;
struct fwnode_handle *fn = dev->fwnode;
if (fwnode) {
@@ -4278,7 +4279,8 @@ void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
} else {
if (fwnode_is_primary(fn)) {
dev->fwnode = fn->secondary;
- fn->secondary = ERR_PTR(-ENODEV);
+ if (!(parent && fn == parent->fwnode))
+ fn->secondary = ERR_PTR(-ENODEV);
} else {
dev->fwnode = NULL;
}
--
2.28.0
next prev parent reply other threads:[~2020-10-22 18:41 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-22 18:40 [PATCH v1 1/2] device property: Keep secondary firmware node secondary by type Andy Shevchenko
2020-10-22 18:41 ` Andy Shevchenko [this message]
2020-10-23 12:35 ` [PATCH v1 2/2] device property: Don't clear secondary pointer for shared primary firmware node Heikki Krogerus
2020-10-23 14:03 ` Ferry Toth
2020-10-23 14:16 ` Ferry Toth
2020-10-23 12:34 ` [PATCH v1 1/2] device property: Keep secondary firmware node secondary by type Heikki Krogerus
2020-10-23 14:16 ` Ferry Toth
[not found] ` <ef59c911-8d8b-783a-c756-05123f428302@gmail.com>
2020-10-23 14:19 ` Andy Shevchenko
2020-10-27 18:21 ` Rafael J. Wysocki
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