When interface stopped while running intensive Rx traffic, the following oops
observed:

[89846.734683] Call trace:
[89846.737117] [<ffffffc00083aa64>] dev_gro_receive+0xac/0x358
[89846.742674] [<ffffffc00083ae94>] napi_gro_receive+0x24/0xa4
[89846.748251] [<ffffffbffc1c2f88>] $x+0xec/0x1f8 [wil6210]         wil_netif_rx_any
[89846.753547] [<ffffffbffc1c4830>] $x+0x34/0x54 [wil6210]          wil_release_reorder_frame
[89846.758755] [<ffffffbffc1c48ac>] wil_release_reorder_frames+0x5c/0x78 [wil6210]
[89846.766044] [<ffffffbffc1c4bf8>] wil_tid_ampdu_rx_free+0x20/0x48 [wil6210]
[89846.772901] [<ffffffbffc1bedc8>] $x+0x190/0x1e8 [wil6210]
[89846.778285] [<ffffffbffc1c0ed4>] wmi_event_worker+0x230/0x2f8 [wil6210]
[89846.784865] [<ffffffc0000b0bc8>] process_one_work+0x278/0x3fc
[89846.790591] [<ffffffc0000b1218>] worker_thread+0x200/0x330
[89846.796060] [<ffffffc0000b6664>] kthread+0xac/0xb8
[89846.800836] Code: b940c661 f9406a62 8b010041 f9400026 (f8636882)
[89846.807008] ---[ end trace d6fdc17cd27d18f6 ]---

Reason is the following: when removing Rx vring
(wil_netdev_ops.ndo_stop -> wil_stop -> wil_down -> __wil_down -> wil_rx_fini),
Rx interrupt occurs. It trigger Rx NAPI, calling wil_rx_handle() that reaps
(already cleaned) buffer, causing skb referring to garbage memory being set into reorder buffer.
Then, network stack trying to access this buffer and fails.

Prevent Rx NAPI from being scheduled if device going to stop. Bit wil_status_napi_en reflects
NAPI enablement state, check it when triggering Rx NAPI.

Testing shows that check for wil_status_napi_en sometimes gets negative, and new error message
get printed - in this case kernel oops would be observed. Original oops is no more reproducible.

This change requires also changes in the AP flows.
Properly enable/disable NAPI for the AP. Make sure Rx VRING is disabled
when resetting target.

For this, promote __wil_up() and __wil_down() to the module scope, and use it
in the relevant flows.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

To better reflect real action performed, rename:
s/wil6210_disable_irq/wil_mask_irq/
s/wil6210_enable_irq/wil_unmask_irq/
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

re-use of wmi_ready for both FW ready event and for wmi_call was causing
false "FW not ready" indication in case wmi_call() was invoked while reset
took place.
add wmi_call completion variable instead of re-using wmi_ready.
Signed-off-by: NDedy Lansky <qca_dlansky@qca.qualcomm.com>
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

While handling Rx packet, BACK event arrives and frees tid_ampdu_rx array.
This causes kernel panic while accessing already freed spinlock

The fix is to remove tid_ampdu_rx[]'s spinlock and instead use single
sta's spinlock to guard the whole tid_ampdu_rx array.
Signed-off-by: NDedy Lansky <qca_dlansky@qca.qualcomm.com>
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Driver disabled PCI master before making sure HW is idle.
This caused memory corruption in case HW access system memory after
PCI master got disabled.
The fix is to change uninit sequence. Make sure FW/HW is idle before
disabling PCI
Signed-off-by: NDedy Lansky <qca_dlansky@qca.qualcomm.com>
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

added misc printouts in some init/uninit functions for better traceability
Signed-off-by: NDedy Lansky <qca_dlansky@qca.qualcomm.com>
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

New module (wil_platform) for handling platform specific tasks
Signed-off-by: NDedy Lansky <qca_dlansky@qca.qualcomm.com>
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

- parentheses, indentation, typos
- seq_puts() instead of seq_printf() with single argument
- sizeof(var) vs. sizeof(type)
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Firmware download implemented but is still experimental feature;
flag controlling it added, no_fw_load. It is true by default,
use no_fw_load=N to activate feature.

Reset flows also got some adjustment for the fw download to work
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Typical time for hardware reset, as measured, is about 200..250 msec.
Adjust sleeping to use more relaxed msleep, increase sleep interval
and increase total sleep time to be about 1sec
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When resetting target in wil_target_reset(), error may occur.
Indicate error via error code. In case of error, don't attempt to further
interact with card, specifically don't attempt firmware download or
interrupts enabling.

Move wil_rx_fini() to be always executed to prevent memory leak.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Fix Copyright headers in all files changed in 2014, to mention 2014
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

It is important to halt USER CPU first, then MAC CPU
Otherwise, race happens in the firmware
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

New hardware release appears; it require some changes to properly support  it.
Introduce struct wil_board and "board" attribute in wil6210_priv;
keep hardware variant information in this structure.
fill it on probe(). Used in the reset flow.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Provide both event (netif_tx_[stop|wake]) tracking via printk;
and state via debugfs 'info'
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

For the AP-like interface, if "disconnect all" requested,
every station should be deleted with cfg80211_del_sta().
Implement this behavior.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

If scan has not finished in some reasonable time (10sec), interpret it as
if firmware error occurs but was not reported. Firmware should report
scan completion for every scan request, so it is error condition indeed.
Perform firmware recovery procedure.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

In case there is something fundamentally wrong with the firmware
(example: RF cable disconnected), FW will always crash immediately
after reset. This leads to infinite fw error recovery loop.

Count consecutive unsuccessful error recovery attempts in a short period
of time, and stop doing recovery after some reasonable count.
It is still possible to manually reset fw doing
interface down/up sequence.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This propagates through all the drivers and mac80211.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Reshuffle prints to consolidate firmware/hardware information
report upon card init

Convert print for unhandled MISC ISR bits to "debug" - it is
normal situation and not an "error"
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When disconnecting some CID, corresponded Tx vring get released. During vring
release, all descriptors get freed. It is possible that Tx NAPI working on the same
vring simultaneously. If it happens, descriptor may be double freed.

To protect from the race above, make sure NAPI won't process the same vring.
Introduce 'enabled' flag in the struct vring_tx_data. Proceed with Tx NAPI only if
'enabled' flag set. Prior to Tx vring release, clear this flag and make sure NAPI
get synchronized.

NAPI enablement status protected by wil->mutex, add protection where it was
missing and check for it.

During reset, disconnect all peers first, then proceed with the Rx vring. It allows for
the disconnect flow to observe proper 'wil->status' and correctly notify cfg80211 about
connection status change
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

make sure reset flow executed in order
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Use 'real' indication for hardware state.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

These methods can change device state, serialize with others
similar ones like up/down
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

upon fw error interrupt - in STA mode, disconnect/cancel scan and
then reset FW/HW
added module param - no_fw_recovery which is false by default
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

wil_reset() removes vring's
At the same time NAPI may be active performing Rx/Tx completion.
If this happens, Rx/Tx polling functions going to access already removed vrings

Make sure NAPI is idle and won't be started prior to vring removal.
For this, track NAPI enabled state
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When switching between STA and AP modes, memory allocated for Rx vring leaks
This is because start_ap() allocates Rx vring but stop_ap() do not free it.
Logically, Rx vring is not valid (HW can't use it anymore), so free it in reset()
Also, check double init for Rx vring and bail out with -EINVAL
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Configure hardware to perform full reset on "power good". This mean,
reset HW on system boot. This improves card stability.
By default this is off.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Put all registers in order for easier navigation;
fix naming to reflect hardware cluster
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Useful to detect hardware problems
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Support for new chip revision. Revision read from the
internal register, PCIE config's "revision id" register
do not indicate HW version properly
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

New firmware do support scan while connected. Enable it.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When connection established, as reported by WMI_CONNECT_EVENTID,
4-way handshaking required for the secure connection is not done
yet. It is indicated by another WMI event. Wait for it and only then
allow data traffic. In case of non-secure connection, FW reports
"data port open" immediately after connection.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

implement del_station() method in the struct cfg80211_ops
It allows to disconnect single peer from the AP
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Disconnect event reported by the FW, should lead to disconnection
of only requested peer. Find for the appropriate CID and disconnect
only it

For AP-like interface, notify cfg80211 with del_sta(),
for the client type interface, disconnect and turn link off.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

There are 24 possible Tx vrings; when doind multiple connections, more then
one vring has to be used. Search for free one and select it.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When running multiple connections, hardware can't do BACK reordering
and it should be done on the host.

Model after mac80211's implementation. Drop RCU for now;
to be re-added when BACK will be stabilized

BACK handshaking is not implemented yet in the hardware,
pretend it was done to support the way FW operating
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Enable multiple (up to 8 - HW/FW limitation) simultaneous connections.
Each connection has its own CID (connection ID) that describes chip's
beam-forming entity. Tx Vring should refer to correct CID for frame to reach
its destination.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>