Problems with mwifiex_pcie firmware activation

[Stanislaw Gruszka <sgruszka@redhat.com>]

I have two systems with this device:

03:00.0 Ethernet controller [0200]: Marvell Technology Group Ltd. 88W8897 [AVASTAR] 802.11ac Wireless [11ab:2b38]
	Flags: bus master, fast devsel, latency 0, IRQ 92
	Memory at 90700000 (64-bit, prefetchable) [size=1M]
	Memory at 90600000 (64-bit, prefetchable) [size=1M]
	Capabilities: [40] Power Management version 3
	Capabilities: [50] MSI: Enable+ Count=1/32 Maskable+ 64bit+
	Capabilities: [70] Express Endpoint, MSI 00
	Capabilities: [100] Advanced Error Reporting
	Capabilities: [140] Device Serial Number 00-00-00-00-00-00-00-00
	Capabilities: [150] Power Budgeting <?>
	Capabilities: [160] Latency Tolerance Reporting
	Capabilities: [168] L1 PM Substates
	Kernel driver in use: mwifiex_pcie

Originally mwifiex_pcie driver from linux-4.7-rc3 fails to initialize
the device with messages:

[   18.057875] mwifiex_pcie: try set_consistent_dma_mask(32)
[   18.068694] mwifiex_pcie: PCI memory map Virt0: ffffc90000c00000 PCI memory map Virt2: ffffc90001c00000
[   18.089754] mwifiex: rx work enabled, cpus 2
[   18.317941] mwifiex_pcie 0000:02:00.0: PCI-E is not the winner <0x0,0>, exit dnld
[   18.325531] mwifiex_pcie 0000:02:00.0: WLAN is not the winner! Skip FW dnld
[   33.460842] mwifiex_pcie 0000:02:00.0: FW failed to be active in time
[   33.467424] mwifiex_pcie 0000:02:00.0: info: mwifiex_fw_dpc: unregister device

On one system, I modify driver to skip check_winner_status() in
mwifiex_dnld_fw() i.e. force firmware upload to device. On first boot
of that modified kernel, system soft hang - there was very long
or infinite loop on some mwifiex procedure (I fail to get exact 
logs from this problem). On second boot, soft hang was gone and
device still fail (with different messages): 

[    8.167830] mwifiex_pcie: try set_consistent_dma_mask(32)
[    8.174098] mwifiex_pcie: PCI memory map Virt0: ffffc90001c00000 PCI memory map Virt2: ffffc90001e00000
[    8.195099] mwifiex: rx work enabled, cpus 2
[    9.595060] mwifiex_pcie 0000:03:00.0: info: FW download over, size 820212 bytes
[    9.714066] mwifiex_pcie 0000:03:00.0: FW failed to be active in time
[    9.720598] mwifiex_pcie 0000:03:00.0: info: mwifiex_fw_dpc: unregister device

However now on unmodified kernel on the same system, driver is capable
to initialize the device:

[    8.751231] mwifiex_pcie: try set_consistent_dma_mask(32)
[    8.792175] mwifiex_pcie: PCI memory map Virt0: ffffc90001c00000 PCI memory map Virt2: ffffc90001e00000
[    8.814868] mwifiex: rx work enabled, cpus 2
[   10.218692] mwifiex_pcie 0000:03:00.0: info: FW download over, size 820212 bytes
[   10.937332] mwifiex_pcie 0000:03:00.0: WLAN FW is active
[   11.052624] mwifiex_pcie 0000:03:00.0: info: MWIFIEX VERSION: mwifiex 1.0 (15.68.7.p77) 
[   11.060810] mwifiex_pcie 0000:03:00.0: driver_version = mwifiex 1.0 (15.68.7.p77) 
[   11.218702] mwifiex_pcie 0000:03:00.0 wlp3s0: renamed from mlan0

Hence looks like forcing firmware upload somehow changed device, now it
is capable to initialize. On my second system device is on pristine state
and original problem is still reproducible. Do you have good solution
for this problem ?

Thanks
Stanislaw