The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 25e9fbf0fd38868a429feabc38abebfc6dbf6542 Mon Sep 17 00:00:00 2001
From: "Isaac J. Manjarres" <isaacmanjarres(a)google.com>
Date: Wed, 17 Aug 2022 11:40:26 -0700
Subject: [PATCH] driver core: Don't probe devices after bus_type.match() probe
deferral
Both __device_attach_driver() and __driver_attach() check the return
code of the bus_type.match() function to see if the device needs to be
added to the deferred probe list. After adding the device to the list,
the logic attempts to bind the device to the driver anyway, as if the
device had matched with the driver, which is not correct.
If __device_attach_driver() detects that the device in question is not
ready to match with a driver on the bus, then it doesn't make sense for
the device to attempt to bind with the current driver or continue
attempting to match with any of the other drivers on the bus. So, update
the logic in __device_attach_driver() to reflect this.
If __driver_attach() detects that a driver tried to match with a device
that is not ready to match yet, then the driver should not attempt to bind
with the device. However, the driver can still attempt to match and bind
with other devices on the bus, as drivers can be bound to multiple
devices. So, update the logic in __driver_attach() to reflect this.
Fixes: 656b8035b0ee ("ARM: 8524/1: driver cohandle -EPROBE_DEFER from bus_type.match()")
Cc: stable(a)vger.kernel.org
Cc: Saravana Kannan <saravanak(a)google.com>
Reported-by: Guenter Roeck <linux(a)roeck-us.net>
Tested-by: Guenter Roeck <linux(a)roeck-us.net>
Tested-by: Linus Walleij <linus.walleij(a)linaro.org>
Reviewed-by: Saravana Kannan <saravanak(a)google.com>
Signed-off-by: Isaac J. Manjarres <isaacmanjarres(a)google.com>
Link: https://lore.kernel.org/r/20220817184026.3468620-1-isaacmanjarres@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index a8916d1bfdcb..ec69b43f926a 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -911,6 +911,11 @@ static int __device_attach_driver(struct device_driver *drv, void *_data)
dev_dbg(dev, "Device match requests probe deferral\n");
dev->can_match = true;
driver_deferred_probe_add(dev);
+ /*
+ * Device can't match with a driver right now, so don't attempt
+ * to match or bind with other drivers on the bus.
+ */
+ return ret;
} else if (ret < 0) {
dev_dbg(dev, "Bus failed to match device: %d\n", ret);
return ret;
@@ -1150,6 +1155,11 @@ static int __driver_attach(struct device *dev, void *data)
dev_dbg(dev, "Device match requests probe deferral\n");
dev->can_match = true;
driver_deferred_probe_add(dev);
+ /*
+ * Driver could not match with device, but may match with
+ * another device on the bus.
+ */
+ return 0;
} else if (ret < 0) {
dev_dbg(dev, "Bus failed to match device: %d\n", ret);
return ret;
The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From fe8f65b018effbf473f53af3538d0c1878b8b329 Mon Sep 17 00:00:00 2001
From: SeongJae Park <sj(a)kernel.org>
Date: Wed, 31 Aug 2022 16:58:24 +0000
Subject: [PATCH] xen-blkfront: Cache feature_persistent value before
advertisement
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Xen blkfront advertises its support of the persistent grants feature
when it first setting up and when resuming in 'talk_to_blkback()'.
Then, blkback reads the advertised value when it connects with blkfront
and decides if it will use the persistent grants feature or not, and
advertises its decision to blkfront. Blkfront reads the blkback's
decision and it also makes the decision for the use of the feature.
Commit 402c43ea6b34 ("xen-blkfront: Apply 'feature_persistent' parameter
when connect"), however, made the blkfront's read of the parameter for
disabling the advertisement, namely 'feature_persistent', to be done
when it negotiate, not when advertise. Therefore blkfront advertises
without reading the parameter. As the field for caching the parameter
value is zero-initialized, it always advertises as the feature is
disabled, so that the persistent grants feature becomes always disabled.
This commit fixes the issue by making the blkfront does parmeter caching
just before the advertisement.
Fixes: 402c43ea6b34 ("xen-blkfront: Apply 'feature_persistent' parameter when connect")
Cc: <stable(a)vger.kernel.org> # 5.10.x
Reported-by: Marek Marczykowski-Górecki <marmarek(a)invisiblethingslab.com>
Signed-off-by: SeongJae Park <sj(a)kernel.org>
Tested-by: Marek Marczykowski-Górecki <marmarek(a)invisiblethingslab.com>
Reviewed-by: Juergen Gross <jgross(a)suse.com>
Link: https://lore.kernel.org/r/20220831165824.94815-4-sj@kernel.org
Signed-off-by: Juergen Gross <jgross(a)suse.com>
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 276b2ee2a155..1f85750f981e 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -1759,6 +1759,12 @@ static int write_per_ring_nodes(struct xenbus_transaction xbt,
return err;
}
+/* Enable the persistent grants feature. */
+static bool feature_persistent = true;
+module_param(feature_persistent, bool, 0644);
+MODULE_PARM_DESC(feature_persistent,
+ "Enables the persistent grants feature");
+
/* Common code used when first setting up, and when resuming. */
static int talk_to_blkback(struct xenbus_device *dev,
struct blkfront_info *info)
@@ -1850,6 +1856,7 @@ static int talk_to_blkback(struct xenbus_device *dev,
message = "writing protocol";
goto abort_transaction;
}
+ info->feature_persistent_parm = feature_persistent;
err = xenbus_printf(xbt, dev->nodename, "feature-persistent", "%u",
info->feature_persistent_parm);
if (err)
@@ -1919,12 +1926,6 @@ static int negotiate_mq(struct blkfront_info *info)
return 0;
}
-/* Enable the persistent grants feature. */
-static bool feature_persistent = true;
-module_param(feature_persistent, bool, 0644);
-MODULE_PARM_DESC(feature_persistent,
- "Enables the persistent grants feature");
-
/*
* Entry point to this code when a new device is created. Allocate the basic
* structures and the ring buffer for communication with the backend, and
@@ -2284,7 +2285,6 @@ static void blkfront_gather_backend_features(struct blkfront_info *info)
if (xenbus_read_unsigned(info->xbdev->otherend, "feature-discard", 0))
blkfront_setup_discard(info);
- info->feature_persistent_parm = feature_persistent;
if (info->feature_persistent_parm)
info->feature_persistent =
!!xenbus_read_unsigned(info->xbdev->otherend,