If hv_netvsc driver is removed and reloaded, the NET_DEVICE_REGISTER
handler cannot perform VF register successfully as the register call
is received before netvsc_probe is finished. This is because we
register register_netdevice_notifier() very early(even before
vmbus_driver_register()).
To fix this, we try to register each such matching VF( if it is visible
as a netdevice) at the end of netvsc_probe.
Cc: stable(a)vger.kernel.org
Fixes: 85520856466e ("hv_netvsc: Fix race of register_netdevice_notifier and VF register")
Suggested-by: Dexuan Cui <decui(a)microsoft.com>
Signed-off-by: Shradha Gupta <shradhagupta(a)linux.microsoft.com>
Tested-on: Ubuntu22
Testcases: LISA testsuites
verify_reload_hyperv_modules, perf_tcp_ntttcp_sriov
---
drivers/net/hyperv/netvsc_drv.c | 49 ++++++++++++++++++++++++++++-----
1 file changed, 42 insertions(+), 7 deletions(-)
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 706ea5263e87..25c4dc9cc4bd 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -42,6 +42,10 @@
#define LINKCHANGE_INT (2 * HZ)
#define VF_TAKEOVER_INT (HZ / 10)
+/* Macros to define the context of vf registration */
+#define VF_REG_IN_PROBE 1
+#define VF_REG_IN_RECV_CBACK 2
+
static unsigned int ring_size __ro_after_init = 128;
module_param(ring_size, uint, 0444);
MODULE_PARM_DESC(ring_size, "Ring buffer size (# of pages)");
@@ -2183,7 +2187,7 @@ static rx_handler_result_t netvsc_vf_handle_frame(struct sk_buff **pskb)
}
static int netvsc_vf_join(struct net_device *vf_netdev,
- struct net_device *ndev)
+ struct net_device *ndev, int context)
{
struct net_device_context *ndev_ctx = netdev_priv(ndev);
int ret;
@@ -2205,8 +2209,11 @@ static int netvsc_vf_join(struct net_device *vf_netdev,
ndev->name, ret);
goto upper_link_failed;
}
-
- schedule_delayed_work(&ndev_ctx->vf_takeover, VF_TAKEOVER_INT);
+ /* If this registration is called from probe context vf_takeover
+ * is taken care of later in probe itself.
+ */
+ if (context == VF_REG_IN_RECV_CBACK)
+ schedule_delayed_work(&ndev_ctx->vf_takeover, VF_TAKEOVER_INT);
call_netdevice_notifiers(NETDEV_JOIN, vf_netdev);
@@ -2344,7 +2351,7 @@ static int netvsc_prepare_bonding(struct net_device *vf_netdev)
return NOTIFY_DONE;
}
-static int netvsc_register_vf(struct net_device *vf_netdev)
+static int netvsc_register_vf(struct net_device *vf_netdev, int context)
{
struct net_device_context *net_device_ctx;
struct netvsc_device *netvsc_dev;
@@ -2384,7 +2391,7 @@ static int netvsc_register_vf(struct net_device *vf_netdev)
netdev_info(ndev, "VF registering: %s\n", vf_netdev->name);
- if (netvsc_vf_join(vf_netdev, ndev) != 0)
+ if (netvsc_vf_join(vf_netdev, ndev, context) != 0)
return NOTIFY_DONE;
dev_hold(vf_netdev);
@@ -2485,7 +2492,7 @@ static int netvsc_unregister_vf(struct net_device *vf_netdev)
static int netvsc_probe(struct hv_device *dev,
const struct hv_vmbus_device_id *dev_id)
{
- struct net_device *net = NULL;
+ struct net_device *net = NULL, *vf_netdev;
struct net_device_context *net_device_ctx;
struct netvsc_device_info *device_info = NULL;
struct netvsc_device *nvdev;
@@ -2597,6 +2604,34 @@ static int netvsc_probe(struct hv_device *dev,
}
list_add(&net_device_ctx->list, &netvsc_dev_list);
+
+ /* When the hv_netvsc driver is removed and readded, the
+ * NET_DEVICE_REGISTER for the vf device is replayed before probe
+ * is complete. This is because register_netdevice_notifier() gets
+ * registered before vmbus_driver_register() so that callback func
+ * is set before probe and we don't miss events like NETDEV_POST_INIT
+ * So, in this section we try to register each matching
+ * vf device that is present as a netdevice, knowing that it's register
+ * call is not processed in the netvsc_netdev_notifier(as probing is
+ * progress and get_netvsc_byslot fails).
+ */
+ for_each_netdev(dev_net(net), vf_netdev) {
+ if (vf_netdev->netdev_ops == &device_ops)
+ continue;
+
+ if (vf_netdev->type != ARPHRD_ETHER)
+ continue;
+
+ if (is_vlan_dev(vf_netdev))
+ continue;
+
+ if (netif_is_bond_master(vf_netdev))
+ continue;
+
+ netvsc_prepare_bonding(vf_netdev);
+ netvsc_register_vf(vf_netdev, VF_REG_IN_PROBE);
+ __netvsc_vf_setup(net, vf_netdev);
+ }
rtnl_unlock();
netvsc_devinfo_put(device_info);
@@ -2773,7 +2808,7 @@ static int netvsc_netdev_event(struct notifier_block *this,
case NETDEV_POST_INIT:
return netvsc_prepare_bonding(event_dev);
case NETDEV_REGISTER:
- return netvsc_register_vf(event_dev);
+ return netvsc_register_vf(event_dev, VF_REG_IN_RECV_CBACK);
case NETDEV_UNREGISTER:
return netvsc_unregister_vf(event_dev);
case NETDEV_UP:
--
2.34.1
From: Linus Torvalds <torvalds(a)linux-foundation.org>
The dentry lookup for eventfs files was very broken, and had lots of
signs of the old situation where the filesystem names were all created
statically in the dentry tree, rather than being looked up dynamically
based on the eventfs data structures.
You could see it in the naming - how it claimed to "create" dentries
rather than just look up the dentries that were given it.
You could see it in various nonsensical and very incorrect operations,
like using "simple_lookup()" on the dentries that were passed in, which
only results in those dentries becoming negative dentries. Which meant
that any other lookup would possibly return ENOENT if it saw that
negative dentry before the data was then later filled in.
You could see it in the immense amount of nonsensical code that didn't
actually just do lookups.
Link: https://lore.kernel.org/linux-trace-kernel/202401291043.e62e89dc-oliver.san…
Cc: stable(a)vger.kernel.org
Fixes: c1504e510238 ("eventfs: Implement eventfs dir creation functions")
Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org>
Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org>
---
Changes since v1: https://lore.kernel.org/linux-trace-kernel/20240130190355.11486-3-torvalds@…
- Fixed the lookup case of not found dentry, to return an error.
This was added in a later patch when it should have been in this one.
- Removed the calls to eventfs_{start,end,failed}_creating()
fs/tracefs/event_inode.c | 285 ++++++++-------------------------------
fs/tracefs/inode.c | 69 ----------
fs/tracefs/internal.h | 3 -
3 files changed, 58 insertions(+), 299 deletions(-)
diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c
index e9819d719d2a..4878f4d578be 100644
--- a/fs/tracefs/event_inode.c
+++ b/fs/tracefs/event_inode.c
@@ -230,7 +230,6 @@ static struct eventfs_inode *eventfs_find_events(struct dentry *dentry)
{
struct eventfs_inode *ei;
- mutex_lock(&eventfs_mutex);
do {
// The parent is stable because we do not do renames
dentry = dentry->d_parent;
@@ -247,7 +246,6 @@ static struct eventfs_inode *eventfs_find_events(struct dentry *dentry)
}
// Walk upwards until you find the events inode
} while (!ei->is_events);
- mutex_unlock(&eventfs_mutex);
update_top_events_attr(ei, dentry->d_sb);
@@ -280,11 +278,10 @@ static void update_inode_attr(struct dentry *dentry, struct inode *inode,
}
/**
- * create_file - create a file in the tracefs filesystem
- * @name: the name of the file to create.
+ * lookup_file - look up a file in the tracefs filesystem
+ * @dentry: the dentry to look up
* @mode: the permission that the file should have.
* @attr: saved attributes changed by user
- * @parent: parent dentry for this file.
* @data: something that the caller will want to get to later on.
* @fop: struct file_operations that should be used for this file.
*
@@ -292,13 +289,13 @@ static void update_inode_attr(struct dentry *dentry, struct inode *inode,
* directory. The inode.i_private pointer will point to @data in the open()
* call.
*/
-static struct dentry *create_file(const char *name, umode_t mode,
+static struct dentry *lookup_file(struct dentry *dentry,
+ umode_t mode,
struct eventfs_attr *attr,
- struct dentry *parent, void *data,
+ void *data,
const struct file_operations *fop)
{
struct tracefs_inode *ti;
- struct dentry *dentry;
struct inode *inode;
if (!(mode & S_IFMT))
@@ -307,15 +304,9 @@ static struct dentry *create_file(const char *name, umode_t mode,
if (WARN_ON_ONCE(!S_ISREG(mode)))
return NULL;
- WARN_ON_ONCE(!parent);
- dentry = eventfs_start_creating(name, parent);
-
- if (IS_ERR(dentry))
- return dentry;
-
inode = tracefs_get_inode(dentry->d_sb);
if (unlikely(!inode))
- return eventfs_failed_creating(dentry);
+ return ERR_PTR(-ENOMEM);
/* If the user updated the directory's attributes, use them */
update_inode_attr(dentry, inode, attr, mode);
@@ -329,32 +320,29 @@ static struct dentry *create_file(const char *name, umode_t mode,
ti = get_tracefs(inode);
ti->flags |= TRACEFS_EVENT_INODE;
- d_instantiate(dentry, inode);
+
+ d_add(dentry, inode);
fsnotify_create(dentry->d_parent->d_inode, dentry);
- return eventfs_end_creating(dentry);
+ return dentry;
};
/**
- * create_dir - create a dir in the tracefs filesystem
+ * lookup_dir_entry - look up a dir in the tracefs filesystem
+ * @dentry: the directory to look up
* @ei: the eventfs_inode that represents the directory to create
- * @parent: parent dentry for this file.
*
- * This function will create a dentry for a directory represented by
+ * This function will look up a dentry for a directory represented by
* a eventfs_inode.
*/
-static struct dentry *create_dir(struct eventfs_inode *ei, struct dentry *parent)
+static struct dentry *lookup_dir_entry(struct dentry *dentry,
+ struct eventfs_inode *pei, struct eventfs_inode *ei)
{
struct tracefs_inode *ti;
- struct dentry *dentry;
struct inode *inode;
- dentry = eventfs_start_creating(ei->name, parent);
- if (IS_ERR(dentry))
- return dentry;
-
inode = tracefs_get_inode(dentry->d_sb);
if (unlikely(!inode))
- return eventfs_failed_creating(dentry);
+ return ERR_PTR(-ENOMEM);
/* If the user updated the directory's attributes, use them */
update_inode_attr(dentry, inode, &ei->attr,
@@ -371,11 +359,14 @@ static struct dentry *create_dir(struct eventfs_inode *ei, struct dentry *parent
/* Only directories have ti->private set to an ei, not files */
ti->private = ei;
+ dentry->d_fsdata = ei;
+ ei->dentry = dentry; // Remove me!
+
inc_nlink(inode);
- d_instantiate(dentry, inode);
+ d_add(dentry, inode);
inc_nlink(dentry->d_parent->d_inode);
fsnotify_mkdir(dentry->d_parent->d_inode, dentry);
- return eventfs_end_creating(dentry);
+ return dentry;
}
static void free_ei(struct eventfs_inode *ei)
@@ -425,7 +416,7 @@ void eventfs_set_ei_status_free(struct tracefs_inode *ti, struct dentry *dentry)
}
/**
- * create_file_dentry - create a dentry for a file of an eventfs_inode
+ * lookup_file_dentry - create a dentry for a file of an eventfs_inode
* @ei: the eventfs_inode that the file will be created under
* @idx: the index into the d_children[] of the @ei
* @parent: The parent dentry of the created file.
@@ -438,157 +429,21 @@ void eventfs_set_ei_status_free(struct tracefs_inode *ti, struct dentry *dentry)
* address located at @e_dentry.
*/
static struct dentry *
-create_file_dentry(struct eventfs_inode *ei, int idx,
- struct dentry *parent, const char *name, umode_t mode, void *data,
+lookup_file_dentry(struct dentry *dentry,
+ struct eventfs_inode *ei, int idx,
+ umode_t mode, void *data,
const struct file_operations *fops)
{
struct eventfs_attr *attr = NULL;
struct dentry **e_dentry = &ei->d_children[idx];
- struct dentry *dentry;
-
- WARN_ON_ONCE(!inode_is_locked(parent->d_inode));
- mutex_lock(&eventfs_mutex);
- if (ei->is_freed) {
- mutex_unlock(&eventfs_mutex);
- return NULL;
- }
- /* If the e_dentry already has a dentry, use it */
- if (*e_dentry) {
- dget(*e_dentry);
- mutex_unlock(&eventfs_mutex);
- return *e_dentry;
- }
-
- /* ei->entry_attrs are protected by SRCU */
if (ei->entry_attrs)
attr = &ei->entry_attrs[idx];
- mutex_unlock(&eventfs_mutex);
-
- dentry = create_file(name, mode, attr, parent, data, fops);
-
- mutex_lock(&eventfs_mutex);
-
- if (IS_ERR_OR_NULL(dentry)) {
- /*
- * When the mutex was released, something else could have
- * created the dentry for this e_dentry. In which case
- * use that one.
- *
- * If ei->is_freed is set, the e_dentry is currently on its
- * way to being freed, don't return it. If e_dentry is NULL
- * it means it was already freed.
- */
- if (ei->is_freed) {
- dentry = NULL;
- } else {
- dentry = *e_dentry;
- dget(dentry);
- }
- mutex_unlock(&eventfs_mutex);
- return dentry;
- }
-
- if (!*e_dentry && !ei->is_freed) {
- *e_dentry = dentry;
- dentry->d_fsdata = ei;
- } else {
- /*
- * Should never happen unless we get here due to being freed.
- * Otherwise it means two dentries exist with the same name.
- */
- WARN_ON_ONCE(!ei->is_freed);
- dentry = NULL;
- }
- mutex_unlock(&eventfs_mutex);
-
- return dentry;
-}
-
-/**
- * eventfs_post_create_dir - post create dir routine
- * @ei: eventfs_inode of recently created dir
- *
- * Map the meta-data of files within an eventfs dir to their parent dentry
- */
-static void eventfs_post_create_dir(struct eventfs_inode *ei)
-{
- struct eventfs_inode *ei_child;
-
- lockdep_assert_held(&eventfs_mutex);
-
- /* srcu lock already held */
- /* fill parent-child relation */
- list_for_each_entry_srcu(ei_child, &ei->children, list,
- srcu_read_lock_held(&eventfs_srcu)) {
- ei_child->d_parent = ei->dentry;
- }
-}
-
-/**
- * create_dir_dentry - Create a directory dentry for the eventfs_inode
- * @pei: The eventfs_inode parent of ei.
- * @ei: The eventfs_inode to create the directory for
- * @parent: The dentry of the parent of this directory
- *
- * This creates and attaches a directory dentry to the eventfs_inode @ei.
- */
-static struct dentry *
-create_dir_dentry(struct eventfs_inode *pei, struct eventfs_inode *ei,
- struct dentry *parent)
-{
- struct dentry *dentry = NULL;
-
- WARN_ON_ONCE(!inode_is_locked(parent->d_inode));
-
- mutex_lock(&eventfs_mutex);
- if (pei->is_freed || ei->is_freed) {
- mutex_unlock(&eventfs_mutex);
- return NULL;
- }
- if (ei->dentry) {
- /* If the eventfs_inode already has a dentry, use it */
- dentry = ei->dentry;
- dget(dentry);
- mutex_unlock(&eventfs_mutex);
- return dentry;
- }
- mutex_unlock(&eventfs_mutex);
+ dentry->d_fsdata = ei; // NOTE: ei of _parent_
+ lookup_file(dentry, mode, attr, data, fops);
- dentry = create_dir(ei, parent);
-
- mutex_lock(&eventfs_mutex);
-
- if (IS_ERR_OR_NULL(dentry) && !ei->is_freed) {
- /*
- * When the mutex was released, something else could have
- * created the dentry for this e_dentry. In which case
- * use that one.
- *
- * If ei->is_freed is set, the e_dentry is currently on its
- * way to being freed.
- */
- dentry = ei->dentry;
- if (dentry)
- dget(dentry);
- mutex_unlock(&eventfs_mutex);
- return dentry;
- }
-
- if (!ei->dentry && !ei->is_freed) {
- ei->dentry = dentry;
- eventfs_post_create_dir(ei);
- dentry->d_fsdata = ei;
- } else {
- /*
- * Should never happen unless we get here due to being freed.
- * Otherwise it means two dentries exist with the same name.
- */
- WARN_ON_ONCE(!ei->is_freed);
- dentry = NULL;
- }
- mutex_unlock(&eventfs_mutex);
+ *e_dentry = dentry; // Remove me
return dentry;
}
@@ -607,79 +462,55 @@ static struct dentry *eventfs_root_lookup(struct inode *dir,
struct dentry *dentry,
unsigned int flags)
{
- const struct file_operations *fops;
- const struct eventfs_entry *entry;
struct eventfs_inode *ei_child;
struct tracefs_inode *ti;
struct eventfs_inode *ei;
- struct dentry *ei_dentry = NULL;
- struct dentry *ret = NULL;
- struct dentry *d;
const char *name = dentry->d_name.name;
- umode_t mode;
- void *data;
- int idx;
- int i;
- int r;
+ struct dentry *result = NULL;
ti = get_tracefs(dir);
if (!(ti->flags & TRACEFS_EVENT_INODE))
- return NULL;
-
- /* Grab srcu to prevent the ei from going away */
- idx = srcu_read_lock(&eventfs_srcu);
+ return ERR_PTR(-EIO);
- /*
- * Grab the eventfs_mutex to consistent value from ti->private.
- * This s
- */
mutex_lock(&eventfs_mutex);
- ei = READ_ONCE(ti->private);
- if (ei && !ei->is_freed)
- ei_dentry = READ_ONCE(ei->dentry);
- mutex_unlock(&eventfs_mutex);
-
- if (!ei || !ei_dentry)
- goto out;
- data = ei->data;
+ ei = ti->private;
+ if (!ei || ei->is_freed)
+ goto enoent;
- list_for_each_entry_srcu(ei_child, &ei->children, list,
- srcu_read_lock_held(&eventfs_srcu)) {
+ list_for_each_entry(ei_child, &ei->children, list) {
if (strcmp(ei_child->name, name) != 0)
continue;
- ret = simple_lookup(dir, dentry, flags);
- if (IS_ERR(ret))
- goto out;
- d = create_dir_dentry(ei, ei_child, ei_dentry);
- dput(d);
+ if (ei_child->is_freed)
+ goto enoent;
+ lookup_dir_entry(dentry, ei, ei_child);
goto out;
}
- for (i = 0; i < ei->nr_entries; i++) {
- entry = &ei->entries[i];
- if (strcmp(name, entry->name) == 0) {
- void *cdata = data;
- mutex_lock(&eventfs_mutex);
- /* If ei->is_freed, then the event itself may be too */
- if (!ei->is_freed)
- r = entry->callback(name, &mode, &cdata, &fops);
- else
- r = -1;
- mutex_unlock(&eventfs_mutex);
- if (r <= 0)
- continue;
- ret = simple_lookup(dir, dentry, flags);
- if (IS_ERR(ret))
- goto out;
- d = create_file_dentry(ei, i, ei_dentry, name, mode, cdata, fops);
- dput(d);
- break;
- }
+ for (int i = 0; i < ei->nr_entries; i++) {
+ void *data;
+ umode_t mode;
+ const struct file_operations *fops;
+ const struct eventfs_entry *entry = &ei->entries[i];
+
+ if (strcmp(name, entry->name) != 0)
+ continue;
+
+ data = ei->data;
+ if (entry->callback(name, &mode, &data, &fops) <= 0)
+ goto enoent;
+
+ lookup_file_dentry(dentry, ei, i, mode, data, fops);
+ goto out;
}
+
+ enoent:
+ /* Don't cache negative lookups, just return an error */
+ result = ERR_PTR(-ENOENT);
+
out:
- srcu_read_unlock(&eventfs_srcu, idx);
- return ret;
+ mutex_unlock(&eventfs_mutex);
+ return result;
}
/*
diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c
index 888e42087847..5c84460feeeb 100644
--- a/fs/tracefs/inode.c
+++ b/fs/tracefs/inode.c
@@ -495,75 +495,6 @@ struct dentry *tracefs_end_creating(struct dentry *dentry)
return dentry;
}
-/**
- * eventfs_start_creating - start the process of creating a dentry
- * @name: Name of the file created for the dentry
- * @parent: The parent dentry where this dentry will be created
- *
- * This is a simple helper function for the dynamically created eventfs
- * files. When the directory of the eventfs files are accessed, their
- * dentries are created on the fly. This function is used to start that
- * process.
- */
-struct dentry *eventfs_start_creating(const char *name, struct dentry *parent)
-{
- struct dentry *dentry;
- int error;
-
- /* Must always have a parent. */
- if (WARN_ON_ONCE(!parent))
- return ERR_PTR(-EINVAL);
-
- error = simple_pin_fs(&trace_fs_type, &tracefs_mount,
- &tracefs_mount_count);
- if (error)
- return ERR_PTR(error);
-
- if (unlikely(IS_DEADDIR(parent->d_inode)))
- dentry = ERR_PTR(-ENOENT);
- else
- dentry = lookup_one_len(name, parent, strlen(name));
-
- if (!IS_ERR(dentry) && dentry->d_inode) {
- dput(dentry);
- dentry = ERR_PTR(-EEXIST);
- }
-
- if (IS_ERR(dentry))
- simple_release_fs(&tracefs_mount, &tracefs_mount_count);
-
- return dentry;
-}
-
-/**
- * eventfs_failed_creating - clean up a failed eventfs dentry creation
- * @dentry: The dentry to clean up
- *
- * If after calling eventfs_start_creating(), a failure is detected, the
- * resources created by eventfs_start_creating() needs to be cleaned up. In
- * that case, this function should be called to perform that clean up.
- */
-struct dentry *eventfs_failed_creating(struct dentry *dentry)
-{
- dput(dentry);
- simple_release_fs(&tracefs_mount, &tracefs_mount_count);
- return NULL;
-}
-
-/**
- * eventfs_end_creating - Finish the process of creating a eventfs dentry
- * @dentry: The dentry that has successfully been created.
- *
- * This function is currently just a place holder to match
- * eventfs_start_creating(). In case any synchronization needs to be added,
- * this function will be used to implement that without having to modify
- * the callers of eventfs_start_creating().
- */
-struct dentry *eventfs_end_creating(struct dentry *dentry)
-{
- return dentry;
-}
-
/* Find the inode that this will use for default */
static struct inode *instance_inode(struct dentry *parent, struct inode *inode)
{
diff --git a/fs/tracefs/internal.h b/fs/tracefs/internal.h
index 7d84349ade87..09037e2c173d 100644
--- a/fs/tracefs/internal.h
+++ b/fs/tracefs/internal.h
@@ -80,9 +80,6 @@ struct dentry *tracefs_start_creating(const char *name, struct dentry *parent);
struct dentry *tracefs_end_creating(struct dentry *dentry);
struct dentry *tracefs_failed_creating(struct dentry *dentry);
struct inode *tracefs_get_inode(struct super_block *sb);
-struct dentry *eventfs_start_creating(const char *name, struct dentry *parent);
-struct dentry *eventfs_failed_creating(struct dentry *dentry);
-struct dentry *eventfs_end_creating(struct dentry *dentry);
void eventfs_set_ei_status_free(struct tracefs_inode *ti, struct dentry *dentry);
#endif /* _TRACEFS_INTERNAL_H */
--
2.43.0
From: Jason Gerecke <killertofu(a)gmail.com>
The xf86-input-wacom driver does not treat '0' as a valid serial number
and will drop any input report which contains an MSC_SERIAL = 0 event.
The kernel driver already takes care to avoid sending any MSC_SERIAL
event if the value of serial[0] == 0 (which is the case for devices
that don't actually report a serial number), but this is not quite
sufficient. Only the lower 32 bits of the serial get reported to
userspace, so if this portion of the serial is zero then there can still
be problems.
This commit allows the driver to report either the lower 32 bits if they
are non-zero or the upper 32 bits otherwise.
Signed-off-by: Jason Gerecke <jason.gerecke(a)wacom.com>
Fixes: f85c9dc678a5 ("HID: wacom: generic: Support tool ID and additional tool types")
CC: stable(a)vger.kernel.org # v4.10
---
4.5/wacom_wac.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/4.5/wacom_wac.c b/4.5/wacom_wac.c
index b38094f..5a95891 100644
--- a/4.5/wacom_wac.c
+++ b/4.5/wacom_wac.c
@@ -2601,7 +2601,14 @@ static void wacom_wac_pen_report(struct hid_device *hdev,
wacom_wac->hid_data.tipswitch);
input_report_key(input, wacom_wac->tool[0], sense);
if (wacom_wac->serial[0]) {
- input_event(input, EV_MSC, MSC_SERIAL, wacom_wac->serial[0]);
+ /*
+ * xf86-input-wacom does not accept a serial number
+ * of '0'. Report the low 32 bits if possible, but
+ * if they are zero, report the upper ones instead.
+ */
+ __u32 serial_lo = wacom_wac->serial[0] & 0xFFFFFFFFu;
+ __u32 serial_hi = wacom_wac->serial[0] >> 32;
+ input_event(input, EV_MSC, MSC_SERIAL, serial_lo ? serial_lo : serial_hi);
input_report_abs(input, ABS_MISC, sense ? id : 0);
}
--
2.43.0
Not all mv88e6xxx device support C45 read/write operations. Those
which do not return -EOPNOTSUPP. However, when phylib scans the bus,
it considers this fatal, and the probe of the MDIO bus fails, which in
term causes the mv88e6xxx probe as a whole to fail.
When there is no device on the bus for a given address, the pull up
resistor on the data line results in the read returning 0xffff. The
phylib core code understands this when scanning for devices on the
bus. C45 allows multiple devices to be supported at one address, so
phylib will perform a few reads at each address, so although thought
not the most efficient solution, it is a way to avoid fatal
errors. Make use of this as a minimal fix for stable to fix the
probing problems.
Follow up patches will rework how C45 operates to make it similar to
C22 which considers -ENODEV as a none-fatal, and swap mv88e6xxx to
using this.
Cc: stable(a)vger.kernel.org
Fixes: 743a19e38d02 ("net: dsa: mv88e6xxx: Separate C22 and C45 transactions")
Reported-by: Tim Menninger <tmenninger(a)purestorage.com>
Signed-off-by: Andrew Lunn <andrew(a)lunn.ch>
---
drivers/net/dsa/mv88e6xxx/chip.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index 383b3c4d6f59..614cabb5c1b0 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -3659,7 +3659,7 @@ static int mv88e6xxx_mdio_read_c45(struct mii_bus *bus, int phy, int devad,
int err;
if (!chip->info->ops->phy_read_c45)
- return -EOPNOTSUPP;
+ return 0xffff;
mv88e6xxx_reg_lock(chip);
err = chip->info->ops->phy_read_c45(chip, bus, phy, devad, reg, &val);
--
2.43.0