[PATCH] wifi: brcmfmac: use a 200 ms power save timeout by default

[PATCH] wifi: brcmfmac: use a 200 ms power save timeout by default

[Andre Eikmeyer]

cfg80211 calls set_power_mgmt with timeout -1 when userspace leaves the
dynamic power save timeout to the driver, as NetworkManager does. brcmfmac clamps that to BRCMF_PS_MAX_TIMEOUT_MS, so the firmware
stays awake for 2 s after every frame in PM_FAST mode and rarely sleeps
with the background traffic of a typical network.

Use 200 ms for -1. macOS 15.4.1 sets pm2_sleep_ret to 200 ms on the
BCM4377 of a MacBookAir9,1, seen in a trace of its iovar calls across a
sleep and wake cycle. Measured on a MacBookPro15,1, idle with WLAN
associated:

  pm2_sleep_ret 2000 ms: 11.2 W system power
  pm2_sleep_ret  200 ms:  9.2 W
  WLAN off:               8.8 W

Tested-by: Yossef Osman <Yossef.Osman@proton.me>
Tested-by: Aditya Garg <aditya.garg@linux.dev>
Signed-off-by: Andre Eikmeyer <dev@deq.rocks>
---
The KaiT2en community runs this patch with its kernels, no regression
was reported.

 drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
index 46714d87126..e7b21703e34 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
@@ -88,6 +88,7 @@
 #define BRCMF_ND_INFO_TIMEOUT		msecs_to_jiffies(2000)
 
 #define BRCMF_PS_MAX_TIMEOUT_MS		2000
+#define BRCMF_PS_DEFAULT_TIMEOUT_MS	200
 
 /* Dump obss definitions */
 #define ACS_MSRMNT_DELAY		80
@@ -3378,6 +3379,9 @@ brcmf_cfg80211_set_power_mgmt(struct wiphy *wiphy, struct net_device *ndev,
 			bphy_err(drvr, "error (%d)\n", err);
 	}
 
+	/* cfg80211 passes -1 when userspace asks for no particular timeout */
+	if (timeout < 0)
+		timeout = BRCMF_PS_DEFAULT_TIMEOUT_MS;
 	err = brcmf_fil_iovar_int_set(ifp, "pm2_sleep_ret",
 				min_t(u32, timeout, BRCMF_PS_MAX_TIMEOUT_MS));
 	if (err)

base-commit: 991a73f4909f1348ffb4b38765cdb522a775e4c2