2020-09-22 20:49:29

by Ben Greear

[permalink] [raw]
Subject: [PATCH 1/2] wireless: Add sysfs file to show if radio is unavailable

From: Ben Greear <[email protected]>

While stress-testing an IPQ4019 based AP, sometimes the firmware and/or
radio hardware crashes hard enough that it cannot recover. In this case,
no wifi can work on that radio again until user-space takes some
action (such as reboot, or possibly rmmod/modprobe).

Provide a sysfs file so that watchdog or other tools can check to
see if radios are in such a state and take appropriate action.

Signed-off-by: Ben Greear <[email protected]>
---
include/net/cfg80211.h | 13 +++++++++++++
net/wireless/core.c | 6 ++++++
net/wireless/sysfs.c | 2 ++
3 files changed, 21 insertions(+)

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index d9e6b9fbd95ba..926ba62e4b3e2 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -4778,6 +4778,8 @@ struct wiphy_iftype_akm_suites {
* @max_data_retry_count: maximum supported per TID retry count for
* configuration through the %NL80211_TID_CONFIG_ATTR_RETRY_SHORT and
* %NL80211_TID_CONFIG_ATTR_RETRY_LONG attributes
+ * @unavailable: Has this radio become unavailable for some reason.
+ * 0: It is available, otherwise not.
*/
struct wiphy {
/* assign these fields before you register the wiphy */
@@ -4791,6 +4793,7 @@ struct wiphy {

const struct ieee80211_iface_combination *iface_combinations;
int n_iface_combinations;
+ int unavailable;
u16 software_iftypes;

u16 n_addresses;
@@ -7696,6 +7699,16 @@ void cfg80211_stop_iface(struct wiphy *wiphy, struct wireless_dev *wdev,
*/
void cfg80211_shutdown_all_interfaces(struct wiphy *wiphy);

+/**
+ * cfg80211_set_unavailable - Set value indicating resources have become
+ * unavailable.
+ *
+ * This can happen if firmware crashes during restart, for instance. In this
+ * case, probably module rmmod/modprobe or reboot is required to get the system
+ * functional again.
+ */
+void cfg80211_set_unavailable(struct wiphy *wiphy, int value);
+
/**
* wiphy_ext_feature_set - set the extended feature flag
*
diff --git a/net/wireless/core.c b/net/wireless/core.c
index 354b0ccbdc240..e1c842acab796 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -259,6 +259,12 @@ void cfg80211_stop_nan(struct cfg80211_registered_device *rdev,
rdev->opencount--;
}

+void cfg80211_set_unavailable(struct wiphy *wiphy, int value)
+{
+ wiphy->unavailable = value;
+}
+EXPORT_SYMBOL_GPL(cfg80211_set_unavailable);
+
void cfg80211_shutdown_all_interfaces(struct wiphy *wiphy)
{
struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
diff --git a/net/wireless/sysfs.c b/net/wireless/sysfs.c
index 3ac1f48195d28..077ec8083b887 100644
--- a/net/wireless/sysfs.c
+++ b/net/wireless/sysfs.c
@@ -33,6 +33,7 @@ static ssize_t name ## _show(struct device *dev, \
static DEVICE_ATTR_RO(name)

SHOW_FMT(index, "%d", wiphy_idx);
+SHOW_FMT(unavailable, "%d", wiphy.unavailable);
SHOW_FMT(macaddress, "%pM", wiphy.perm_addr);
SHOW_FMT(address_mask, "%pM", wiphy.addr_mask);

@@ -66,6 +67,7 @@ static DEVICE_ATTR_RO(addresses);

static struct attribute *ieee80211_attrs[] = {
&dev_attr_index.attr,
+ &dev_attr_unavailable.attr,
&dev_attr_macaddress.attr,
&dev_attr_address_mask.attr,
&dev_attr_addresses.attr,
--
2.26.2