Re: [PATCH] ath10k: Limit available channels via DT ieee80211-freq-limit

[Arend van Spriel <arend.vanspriel@broadcom.com>]

+ Rafał

On 7/30/2018 5:39 PM, Sven Eckelmann wrote:
> Tri-band devices (1x 2.4GHz + 2x 5GHz) often incorporate special filters in
> the RX and TX path. These filtered channel can in theory still be used by
> the hardware but the signal strength is reduced so much that it makes no
> sense.
>
> There is already a DT property to limit the available channels but ath10k
> has to manually call this functionality to limit the currrently set wiphy
> channels further.

Wondering whether we can call it in wiphy_register() like below. Not 
sure why we did not explore that with the introduction of it by Rafał. 
Maybe he remembers. I did not find something in that direction in 
patchwork, but may have missed it. I know mt76 drops the band reference 
if it ends up with all channels disabled. Maybe that was the reason.

Regards,
Arend
---
diff --git a/net/wireless/core.c b/net/wireless/core.c
index a88551f..2e00cb1 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -742,6 +742,8 @@ int wiphy_register(struct wiphy *wiphy)
	if (res)
		return res;

+	wiphy_read_of_freq_limits(wiphy);
+
	/* sanity check supported bands/channels */
	for (band = 0; band < NUM_NL80211_BANDS; band++) {
		u16 types = 0;