Adjust gain before scanning

[MartinHruza]

• This patch temporarily increases the rx gain before scanning and reset it back to the last recorded value once the scanning finishes.
• Ref: [RTL8811CU]: Wifi scanning in AP mode with a client connected skips some channels #337

[dubhater]

Looks mostly good to me.

• The initial gain values are backwards: larger values lower the gain, smaller values increase the gain. So 0x1c results in maximum gain and 0x5a results in minimum gain. Using 0x2a helps in your case because normally it's probably choosing ~0x40.

• Another thing I wonder is if you should go lower than rtwdev->chip->dig_min. For some chips it's 0x1c, for others it's 0x20.

• Lastly, you should send the patch to the linux-wireless mailing list. Some more information about that: https://www.kernel.org/doc/html/latest/process/submitting-patches.html

[LuisMitaHL]

Works on rtl8812au

[LuisMitaHL]

Hi, there is any updates on this patch?

[dubhater]

It looks like the author vanished, but anyone can send the patch to the mailing list (with proper credit). Just replace DIG_CVRG_MAX with DIG_CVRG_MIN to make it do what the description says.