Hi, 

I'm a linux noob and realy needs help with my wifi module.
Wireless module driver seems to be installed but no network is showing up.
Bluetooth is also not working.

My machine:

Dell Studio 1747
Dell Wireless WLAN 1520 (Half MiniCard)

OS:

Deepin 20.2.1
Kernel 5.11 (same issue with 5.10)
fresh installation (german language)

lspci:

$ lspci
00:00.0 Host bridge: Intel Corporation Core Processor DMI (rev 11)
00:03.0 PCI bridge: Intel Corporation Core Processor PCI Express Root Port 1 (rev 11)
00:08.0 System peripheral: Intel Corporation Core Processor System Management Registers (rev 11)
00:08.1 System peripheral: Intel Corporation Core Processor Semaphore and Scratchpad Registers (rev 11)
00:08.2 System peripheral: Intel Corporation Core Processor System Control and Status Registers (rev 11)
00:08.3 System peripheral: Intel Corporation Core Processor Miscellaneous Registers (rev 11)
00:10.0 System peripheral: Intel Corporation Core Processor QPI Link (rev 11)
00:10.1 System peripheral: Intel Corporation Core Processor QPI Routing and Protocol Registers (rev 11)
00:1a.0 USB controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 05)
00:1b.0 Audio device: Intel Corporation 5 Series/3400 Series Chipset High Definition Audio (rev 05)
00:1c.0 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 1 (rev 05)
00:1c.1 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 2 (rev 05)
00:1c.2 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 3 (rev 05)
00:1c.3 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 4 (rev 05)
00:1c.4 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 5 (rev 05)
00:1c.5 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 6 (rev 05)
00:1d.0 USB controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 05)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev a5)
00:1f.0 ISA bridge: Intel Corporation PM55 Chipset LPC Interface Controller (rev 05)
00:1f.2 SATA controller: Intel Corporation 5 Series/3400 Series Chipset 6 port SATA AHCI Controller (rev 05)
00:1f.3 SMBus: Intel Corporation 5 Series/3400 Series Chipset SMBus Controller (rev 05)
00:1f.6 Signal processing controller: Intel Corporation 5 Series/3400 Series Chipset Thermal Subsystem (rev 05)
02:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] RV730/M96 [Mobility Radeon HD 4650/5165]
02:00.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] RV710/730 HDMI Audio [Radeon HD 4000 series]
08:00.0 Network controller: Broadcom Inc. and subsidiaries BCM4312 802.11b/g LP-PHY (rev 01)
14:00.0 FireWire (IEEE 1394): O2 Micro, Inc. 1394 OHCI Compliant Host Controller (rev 01)
14:00.1 SD Host controller: O2 Micro, Inc. Integrated MMC/SD Controller (rev 01)
14:00.2 Mass storage controller: O2 Micro, Inc. Integrated MS/MSPRO/xD Controller (rev 01)
20:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 03)
ff:00.0 Host bridge: Intel Corporation Core Processor QuickPath Architecture Generic Non-Core Registers (rev 04)
ff:00.1 Host bridge: Intel Corporation Core Processor QuickPath Architecture System Address Decoder (rev 04)
ff:02.0 Host bridge: Intel Corporation Core Processor QPI Link 0 (rev 04)
ff:02.1 Host bridge: Intel Corporation Core Processor QPI Physical 0 (rev 04)
ff:03.0 Host bridge: Intel Corporation Core Processor Integrated Memory Controller (rev 04)
ff:03.1 Host bridge: Intel Corporation Core Processor Integrated Memory Controller Target Address Decoder (rev 04)
ff:03.4 Host bridge: Intel Corporation Core Processor Integrated Memory Controller Test Registers (rev 04)
ff:04.0 Host bridge: Intel Corporation Core Processor Integrated Memory Controller Channel 0 Control Registers (rev 04)
ff:04.1 Host bridge: Intel Corporation Core Processor Integrated Memory Controller Channel 0 Address Registers (rev 04)
ff:04.2 Host bridge: Intel Corporation Core Processor Integrated Memory Controller Channel 0 Rank Registers (rev 04)
ff:04.3 Host bridge: Intel Corporation Core Processor Integrated Memory Controller Channel 0 Thermal Control Registers (rev 04)
ff:05.0 Host bridge: Intel Corporation Core Processor Integrated Memory Controller Channel 1 Control Registers (rev 04)
ff:05.1 Host bridge: Intel Corporation Core Processor Integrated Memory Controller Channel 1 Address Registers (rev 04)
ff:05.2 Host bridge: Intel Corporation Core Processor Integrated Memory Controller Channel 1 Rank Registers (rev 04)
ff:05.3 Host bridge: Intel Corporation Core Processor Integrated Memory Controller Channel 1 Thermal Control Registers (rev 04)

rfkill list:

rfkill list
0: phy0: Wireless LAN
        Soft blocked: no
        Hard blocked: no
1: brcmwl-0: Wireless LAN
        Soft blocked: no
        Hard blocked: no

Device-manager looks like:

looks like something is wrong with the BCM4312 802.11b/g LP-PHY network adapter.