ath10k: properly return err from start()

If recovery failed ath10k returned 0 (success) and
mac80211 continued to call other driver callbacks.
This caused null dereference.

This is how the failure looked like:

ath10k: ctl_resp never came in (-110)
ath10k: failed to connect to HTC: -110
ath10k: could not init core (-110)
BUG: unable to handle kernel NULL pointer dereference at           (null)
IP: [<ffffffffa0b355c1>] ath10k_ce_send+0x1d/0x15d [ath10k_pci]
PGD 0
Oops: 0000 [#1] PREEMPT SMP
Modules linked in: ath10k_pci ath10k_core ath5k ath9k ath9k_common ath9k_hw ath mac80211 cfg80211 nf_nat_ipv4 ]
CPU: 1 PID: 36 Comm: kworker/1:1 Tainted: G        WC   3.13.0-rc8-wl-ath+ #8
Hardware name: To be filled by O.E.M. To be filled by O.E.M./HURONRIVER, BIOS 4.6.5 05/02/2012
Workqueue: events ieee80211_restart_work [mac80211]
task: ffff880215b521c0 ti: ffff880215e18000 task.ti: ffff880215e18000
RIP: 0010:[<ffffffffa0b355c1>]  [<ffffffffa0b355c1>] ath10k_ce_send+0x1d/0x15d [ath10k_pci]
RSP: 0018:ffff880215e19af8  EFLAGS: 00010292
RAX: ffff880215e19b10 RBX: 0000000000000000 RCX: 0000000000000018
RDX: 00000000d9ccf800 RSI: ffff8800c965ad00 RDI: 0000000000000000
RBP: ffff880215e19b58 R08: 0000000000000002 R09: 0000000000000000
R10: ffffffff812e1a23 R11: 0000000000000292 R12: 0000000000000018
R13: 0000000000000000 R14: 0000000000000002 R15: ffff88021562d700
FS:  0000000000000000(0000) GS:ffff88021fa80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000001a0d000 CR4: 00000000000407e0
Stack:
 d9ccf8000d47df40 ffffffffa0b367a0 ffff880215e19b10 0000000000000010
 ffff880215e19b68 ffff880215e19b28 0000000000000018 ffff8800c965ad00
 0000000000000018 0000000000000000 0000000000000002 ffff88021562d700
Call Trace:
 [<ffffffffa0b3251d>] ath10k_pci_hif_send_head+0xa7/0xcb [ath10k_pci]
 [<ffffffffa0b16cbe>] ath10k_htc_send+0x23d/0x2d0 [ath10k_core]
 [<ffffffffa0b1a169>] ath10k_wmi_cmd_send_nowait+0x5d/0x85 [ath10k_core]
 [<ffffffffa0b1aaef>] ath10k_wmi_cmd_send+0x62/0x115 [ath10k_core]
 [<ffffffff814e8abd>] ? __netdev_alloc_skb+0x4b/0x9b
 [<ffffffffa0b1c438>] ath10k_wmi_vdev_set_param+0x91/0xa3 [ath10k_core]
 [<ffffffffa0b0e0d5>] ath10k_mac_set_rts+0x3e/0x40 [ath10k_core]
 [<ffffffffa0b0e1d0>] ath10k_set_frag_threshold+0x5e/0x9c [ath10k_core]
 [<ffffffffa09d60eb>] ieee80211_reconfig+0x12a/0x7b3 [mac80211]
 [<ffffffff815a8069>] ? mutex_unlock+0x9/0xb
 [<ffffffffa09b3a40>] ieee80211_restart_work+0x5e/0x68 [mac80211]
 [<ffffffff810c01d0>] process_one_work+0x1d7/0x2fc
 [<ffffffff810c0166>] ? process_one_work+0x16d/0x2fc
 [<ffffffff810c06c8>] worker_thread+0x12e/0x1fb
 [<ffffffff810c059a>] ? rescuer_thread+0x27b/0x27b
 [<ffffffff810c5aee>] kthread+0xb5/0xbd
 [<ffffffff815a9220>] ? _raw_spin_unlock_irq+0x28/0x42
 [<ffffffff810c5a39>] ? __kthread_parkme+0x5c/0x5c
 [<ffffffff815ae04c>] ret_from_fork+0x7c/0xb0
 [<ffffffff810c5a39>] ? __kthread_parkme+0x5c/0x5c
Code: df ff d0 48 83 c4 18 5b 41 5c 41 5d 5d c3 55 48 89 e5 41 57 41 56 45 89 c6 41 55 41 54 41 89 cc 53 48 89
RIP  [<ffffffffa0b355c1>] ath10k_ce_send+0x1d/0x15d [ath10k_pci]
 RSP <ffff880215e19af8>
CR2: 0000000000000000

Reported-By: Ben Greear <greearb@candelatech.com>
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
ath10k: configure access category for arp

ARP frames exchange does not work properly for UAPSD enabled AP.
ARP requests which arrives with access category 0 are processed
by network stack and send back with access category 0. FW changes
access category to 6. This is causing problems when UAPSD associated
STA is sleeping after has sent ARP request. Configure ARP access
category in FW to best effort (0) solves this problem. ARP frames
will be send with access category 0.

Simplify arp ac override functionality by removing redundant entry in
pdev param maping table. There should be only one entry in pdev param
map but enum has different name for different FW.

kvalo: change the warning message

Signed-off-by: Marek Puzyniak <marek.puzyniak@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>