mt76_scan_complete() restores the operating channel only if the phy has one.
__mt76_set_channel() is the only function that clears phy->offchannel.
A phy can run a scan while it has no operating channel. A 6 GHz radio with
no configured interface is one example. After such a scan, the flag stays
set.
mt76_txq_schedule_list() skips each TXQ whose wcid points to a phy in this
state. All traffic for the stations on that band stops. The frames stay in
the mac80211 queues. They do not reach the hardware, and no counter shows
them. Only an unrelated channel set clears the flag.
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Felix Fietkau <[email protected]>
The offchannel scan link is allocated in mt76_hw_scan() under
dev->mutex, but torn down without it: mt76_scan_complete() runs from
mt76_scan_work() on the mac80211 workqueue, or from mt76_abort_scan(),
and calls mt76_put_vif_phy_link(), whose vif_link_remove clears the
per-phy omac_mask and the device-wide vif_mask/mld_idx_mask with plain
read-modify-write. A vif link add or remove for another interface,
running concurrently under dev->mutex, can interleave with these
unlocked writes and lose an update: a cleared bit belonging to a live
link gets handed out again (two links sharing an omac/bss/wcid index,
breaking own-MAC unicast RX for the first one), or a freed bit stays
set until reboot and eventually exhausts the index space.
Take dev->mutex around the scan completion, mirroring the ROC teardown
in mt76_roc_complete_work()/mt76_abort_roc(), and switch the channel
restore to __mt76_set_channel() since the caller now holds the lock.
mt76_abort_scan() keeps cancelling the scan work before taking the
mutex, so the work-vs-abort ordering is unchanged.
Signed-off-by: Chad Monroe <[email protected]>
Signed-off-by: Felix Fietkau <[email protected]>
The scan state bit is cleared by mt76_scan_complete(), but nothing ever
sets it: mt76_sw_scan() is only called for drivers without hw scan
support. As a result, all MT76_SCANNING checks are inert for drivers
using mt76_hw_scan(), including the DFS state handling in
mt76_phy_dfs_state() and the guard against manually triggered radar
detection while scanning.
Set the bit when the scan request is accepted. Since every channel
programmed while scanning now evaluates the DFS state as disabled and
stops the radar detector, re-program the operating channel at scan
completion regardless of the off-channel state, after the scanning bit
has been cleared. Otherwise a scan whose last visited channel was the
operating channel, or one that returned to it early because of
associated stations, would leave radar detection stopped until the
next channel switch.
Fixes: 31083e38548f ("wifi: mt76: add code for emulating hardware scanning")
Signed-off-by: Felix Fietkau <[email protected]>
The link_id in info->control.flags is required by mt7996 to select the
correct mt76_wcid for transmission.
Not assigning the link_id in info->control.flags is equivalent to
assigning the link_id to 0, causing mt7996 to select link_id 0 for
transmission, so probe requests sent on behalf of an MLD vif scanning
via a different link were transmitted with the wrong per-link wcid.
Fixes: 31083e38548f ("wifi: mt76: add code for emulating hardware scanning")
Signed-off-by: Michael-CY Lee <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Felix Fietkau <[email protected]>
ieee80211_tx_prepare_skb already frees the skb internally when
invoke_tx_handlers fails, so freeing it again in the caller leads to a
double-free / NULL pointer dereference in skb_release_data.
Signed-off-by: Felix Fietkau <[email protected]>
Prevent mt76_scan_rx_beacon() in softirq from requeuing scan_work
after cancel_delayed_work_sync() returns in mt76_abort_scan(). Without
synchronization, the beacon handler can observe beacon_wait as true
and requeue scan_work between the cancel and the memset in
mt76_scan_complete(), leading to a NULL pointer dereference when
scan_work runs against zeroed scan state.
Introduce scan_lock (placed outside the scan struct to survive the
memset) to make the beacon handler's check-and-queue atomic with
respect to abort_scan's clear of beacon_wait. This eliminates the
race with a single cancel_delayed_work_sync() call.
Signed-off-by: Felix Fietkau <[email protected]>
With chanctx drivers using hardware scan or remain-on-channel,
mac80211 does not know when the radio goes off-channel, which breaks
its software beacon loss detection.
Implement per-link beacon monitoring in the driver. Track the last
beacon timestamp per link and check for beacon loss periodically from
the mac_work handler.
Beacon monitoring is initialized on association and on late link
activation, and cleared on disassociation. The beacon_mon_last
timestamp is reset when returning from offchannel and after channel
switches to prevent false beacon loss detection.
Signed-off-by: Felix Fietkau <[email protected]>
Since mt76 uses chanctx, mac80211 does not send nullfunc power save
notifications when the driver goes offchannel for scan or ROC.
Add mt76_offchannel_notify() to send nullfunc PM=1 before going
offchannel and PM=0 after returning, so that the AP can buffer
frames during the absence.
For MLO, iterate all vif links on the phy and set
IEEE80211_TX_CTRL_MLO_LINK so that the driver's tx_prepare_skb
resolves the correct per-link wcid.
Signed-off-by: Felix Fietkau <[email protected]>
mt76_remain_on_channel() always creates an HT20 chandef and goes
offchannel, even when the ROC channel matches the operating channel.
This unnecessarily narrows bandwidth and triggers beacon stop/restart.
When the ROC channel matches the current operating channel, preserve
the full chandef and skip the offchannel transition, matching the
optimization already present in the scan code.
Extract the shared same-channel detection into mt76_offchannel_chandef()
and use it in both ROC and scan paths.
Signed-off-by: Felix Fietkau <[email protected]>
On channels with NO_IR or RADAR flags, wait for beacon before sending
probe requests. Allows active scanning and WPS on restricted channels
if another AP is already present.
Fixes: c56d6edebc1f ("wifi: mt76: mt7996: use emulated hardware scan support")
Signed-off-by: Chad Monroe <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Felix Fietkau <[email protected]>
avoid unnecessary channel switch when performing an on-channel scan
using a multi-radio device.
Fixes: c56d6edebc1f ("wifi: mt76: mt7996: use emulated hardware scan support")
Signed-off-by: Chad Monroe <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Felix Fietkau <[email protected]>
MediaTek has asked to switch from the ISC license to BSD-3-Clause-Clear,
in order to improve clarity and the legal integrity of the code.
The BSD-3-Clause license includes the "no endorsement" clause, which is
important for protecting the reputation of the original authors and
contributors by preventing unauthorized use of their names for endorsement
purposes.
This clause is absent in the BSD-2-Clause license, which is more permissive
but lacks this specific protection.
This change also cleans up the license of some Kconfig/Makefile files,
which were accidentally marked as GPL.
The GPL 2.0 remains in use on mt76x0, as well as two source files in mt7615
for which the license situation still needs to be clarified.
Signed-off-by: Felix Fietkau <[email protected]>
This allows a driver using the generic channel context functions to
temporarily switch to another channel for off-channel rx/tx.
Signed-off-by: Felix Fietkau <[email protected]>
When scanning on a phy/vif combination that does not have an active link,
create a temporary link in order to ensure that we have a valid wcid.
Signed-off-by: Felix Fietkau <[email protected]>
This adds an implementation for the chanctx functions, which can be used
by multi-channel capable drivers. Preparation for adding MLO support.
Signed-off-by: Felix Fietkau <[email protected]>
Preparation for supporting multiple radios on a single wiphy on devices
where firmware does not support actual hardware scanning.
This is also a prerequisite for full MLO support
Co-developed-by: Peter Chiu <[email protected]>
Signed-off-by: Peter Chiu <[email protected]>
Co-developed-by: Michael-CY Lee <[email protected]>
Signed-off-by: Michael-CY Lee <[email protected]>
Co-developed-by: Shayne Chen <[email protected]>
Signed-off-by: Shayne Chen <[email protected]>
Signed-off-by: Felix Fietkau <[email protected]>
Felix Fietkau