Don't try to process rate section 0 in 5ghz bank. CCK is not used her…

[rhadman]

…e, but by processing 0, baseIndex5G is left unset and can cause a kernel OOPS that looks like:

May 31 23:01:08 rpi2 kernel: [ 2045.373494] RTL871X: No power limit table of the specified band 1, bandwidth 0, ratesection 0, group 0, rf path 0
May 31 23:01:08 rpi2 kernel: [ 2045.373505] RTL871X: use other value 63
May 31 23:01:08 rpi2 kernel: [ 2045.373541] Unable to handle kernel paging request at virtual address 65ce6217
May 31 23:01:08 rpi2 kernel: [ 2045.375393] pgd = b2f98000
May 31 23:01:08 rpi2 kernel: [ 2045.375482] [65ce6217] *pgd=00000000
May 31 23:01:08 rpi2 kernel: [ 2045.375611] Internal error: Oops: 5 [#1] PREEMPT SMP ARM
May 31 23:01:08 rpi2 kernel: [ 2045.376276] CPU: 0 PID: 1311 Comm: wpa_supplicant Tainted: G O 3.18.0-23-rpi2 #24-Ubuntu
May 31 23:01:08 rpi2 kernel: [ 2045.376450] task: b2fe5280 ti: a198c000 task.ti: a198c000
May 31 23:01:08 rpi2 kernel: [ 2045.376724] PC is at PHY_ConvertPowerLimitToPowerIndex+0x540/0x9e8 [8812au]
May 31 23:01:08 rpi2 kernel: [ 2045.376984] LR is at PHY_ConvertPowerLimitToPowerIndex+0x528/0x9e8 [8812au]
May 31 23:01:08 rpi2 kernel: [ 2045.377121] pc : [<7f15493c>] lr : [<7f154924>] psr: 600b0013
May 31 23:01:08 rpi2 kernel: [ 2045.377121] sp : a198dd10 ip : 80913bf0 fp : 0000345c
May 31 23:01:08 rpi2 kernel: [ 2045.377330] r10: 00000000 r9 : 00000000 r8 : b2e72872
May 31 23:01:08 rpi2 kernel: [ 2045.377433] r7 : b2e70000 r6 : b2e72872 r5 : 00000000 r4 : 0000003f
May 31 23:01:08 rpi2 kernel: [ 2045.377559] r3 : 65ce6215 r2 : 00000001 r1 : b2e73450 r0 : 0000001b
May 31 23:01:08 rpi2 kernel: [ 2045.377685] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user
May 31 23:01:08 rpi2 kernel: [ 2045.377821] Control: 10c5387d Table: 32f9806a DAC: 00000015
May 31 23:01:08 rpi2 kernel: [ 2045.377933] Process wpa_supplicant (pid: 1311, stack limit = 0xa198c238)

[rhadman]

Ran into a Oops on a raspberry pi 2 using an Edimax 8812au based device (called "AC600 Wireless Dual-Band Mini USB Adapter"). Looking over the code though, I suspect this Oops can happen on any 5ghz 8812a adapter. The actual crash is on line 983: BW40PwrBasedBm5G = pHalData->TxPwrByRateBase5G[rfPath][baseIndex5G]; where baseIndex5G is whatever happens to be sitting in memory before the loop starts.