Re: [ibm-acpi-devel] [PATCH 1/2] platorm/x86: thinkpad_acpi: sysfs interface to reduce wlan tx power

[Kevin L. <ke...@ke...>]

On Fri, 2021-02-12 at 14:58 +0900, Nitin Joshi wrote:
> Some newer Thinkpads have the WLAN antenna placed close to the WWAN
> antenna. In these cases FCC certification requires that when WWAN is
> active we reduce WLAN transmission power. A new Dynamic Power
> Reduction Control (DPRC) method is available from the BIOS on these
> platforms to reduce or restore WLAN Tx power.
> 
> This patch provides a sysfs interface that userspace can use to adjust the
> WLAN power appropriately.

Question from a user: How does wlan_tx_strength_reduce relate to or
interact with ioctl(SIOCSIWTXPOW) (i.e. iwconfig txpower) and
NL80211_ATTR_WIPHY_TX_POWER_LEVEL (i.e. iw dev set txpower)?  If I
request 30 dBm then enable wlan_tx_strength_reduce, what happens?  Same
in the opposite order?  Will ioctl(SIOCGIWTXPOW) show the reduced
txpower?

Thanks,
Kevin