tech@,

here a patch which introduces support of powersave in a way like it
implemented in iwn and wpi.

I run it for quite some time on:

iwx0 at pci0 dev 20 function 3 "Intel Wi-Fi 6 AX201" rev 0x00, msix

works, no regression or issue noticed.

Ok?

Index: sys/dev/pci/if_iwx.c
===================================================================
RCS file: /home/cvs/src/sys/dev/pci/if_iwx.c,v
diff -u -p -r1.194 if_iwx.c
--- sys/dev/pci/if_iwx.c	1 Dec 2025 16:44:13 -0000	1.194
+++ sys/dev/pci/if_iwx.c	31 Jan 2026 00:39:54 -0000
@@ -406,6 +406,7 @@ void	iwx_power_build_cmd(struct iwx_soft
 	    struct iwx_mac_power_cmd *);
 int	iwx_power_mac_update_mode(struct iwx_softc *, struct iwx_node *);
 int	iwx_power_update_device(struct iwx_softc *);
+int	iwx_set_pslevel(struct iwx_softc *, int, int, int);
 int	iwx_enable_beacon_filter(struct iwx_softc *, struct iwx_node *);
 int	iwx_disable_beacon_filter(struct iwx_softc *);
 int	iwx_add_sta_cmd(struct iwx_softc *, struct iwx_node *, int);
@@ -6645,8 +6646,27 @@ iwx_power_build_cmd(struct iwx_softc *sc
 	keep_alive = roundup(keep_alive, 1000) / 1000;
 	cmd->keep_alive_seconds = htole16(keep_alive);
 
-	if (ic->ic_opmode != IEEE80211_M_MONITOR)
-		cmd->flags = htole16(IWX_POWER_FLAGS_POWER_SAVE_ENA_MSK);
+	if (ic->ic_opmode != IEEE80211_M_MONITOR &&
+	    (ic->ic_flags & IEEE80211_F_PMGTON)) {
+		const struct iwx_pmgt *pmgt;
+		int range;
+
+		if (dtim_period <= 2)
+			range = 0;
+		else if (dtim_period <= 10)
+			range = 1;
+		else
+			range = 2;
+		pmgt = &iwx_pmgt[range][3];
+		cmd->flags = htole16(IWX_POWER_FLAGS_POWER_SAVE_ENA_MSK |
+		    IWX_POWER_FLAGS_POWER_MANAGEMENT_ENA_MSK);
+		cmd->rx_data_timeout = htole32(pmgt->rxtimeout * 1024);
+		cmd->tx_data_timeout = htole32(pmgt->txtimeout * 1024);
+		if (pmgt->skip_dtim != 0) {
+			cmd->flags |= htole16(IWX_POWER_FLAGS_SKIP_OVER_DTIM_MSK);
+			cmd->skip_dtim_periods = pmgt->skip_dtim + 1;
+		}
+	}
 }
 
 int
@@ -6676,7 +6696,8 @@ iwx_power_update_device(struct iwx_softc
 	struct iwx_device_power_cmd cmd = { };
 	struct ieee80211com *ic = &sc->sc_ic;
 
-	if (ic->ic_opmode != IEEE80211_M_MONITOR)
+	if (ic->ic_opmode != IEEE80211_M_MONITOR &&
+	    (ic->ic_flags & IEEE80211_F_PMGTON))
 		cmd.flags = htole16(IWX_DEVICE_POWER_FLAGS_POWER_SAVE_ENA_MSK);
 
 	return iwx_send_cmd_pdu(sc,
@@ -6684,6 +6705,82 @@ iwx_power_update_device(struct iwx_softc
 }
 
 int
+iwx_set_pslevel(struct iwx_softc *sc, int dtim, int level, int async)
+{
+	struct ieee80211com *ic = &sc->sc_ic;
+	struct iwx_device_power_cmd dcmd = { };
+	struct iwx_mac_power_cmd mcmd;
+	struct iwx_node *in;
+	struct ieee80211_node *ni;
+	const struct iwx_pmgt *pmgt;
+	int range, skip_dtim, cmd_flags, err;
+	int dtim_period, dtim_msec, keep_alive;
+
+	if (ic->ic_opmode == IEEE80211_M_MONITOR)
+		return 0;
+
+	if (dtim == 0) {
+		dtim = 1;
+		skip_dtim = 0;
+	} else
+		skip_dtim = -1;
+
+	if (dtim <= 2)
+		range = 0;
+	else if (dtim <= 10)
+		range = 1;
+	else
+		range = 2;
+
+	pmgt = &iwx_pmgt[range][level];
+	if (skip_dtim == -1)
+		skip_dtim = pmgt->skip_dtim;
+
+	if (level != 0)
+		dcmd.flags = htole16(IWX_DEVICE_POWER_FLAGS_POWER_SAVE_ENA_MSK);
+
+	cmd_flags = async ? IWX_CMD_ASYNC : 0;
+	err = iwx_send_cmd_pdu(sc, IWX_POWER_TABLE_CMD, cmd_flags,
+	    sizeof(dcmd), &dcmd);
+	if (err)
+		return err;
+
+	if ((sc->sc_flags & IWX_FLAG_MAC_ACTIVE) == 0)
+		return 0;
+
+	in = (void *)ic->ic_bss;
+	ni = &in->in_ni;
+
+	memset(&mcmd, 0, sizeof(mcmd));
+	mcmd.id_and_color = htole32(IWX_FW_CMD_ID_AND_COLOR(in->in_id,
+	    in->in_color));
+	dtim_period = ni->ni_dtimperiod ? ni->ni_dtimperiod : 1;
+	dtim_msec = dtim_period * ni->ni_intval;
+	keep_alive = MAX(3 * dtim_msec, 1000 * IWX_POWER_KEEP_ALIVE_PERIOD_SEC);
+	keep_alive = roundup(keep_alive, 1000) / 1000;
+	mcmd.keep_alive_seconds = htole16(keep_alive);
+
+	if (level != 0) {
+		mcmd.flags = htole16(IWX_POWER_FLAGS_POWER_SAVE_ENA_MSK |
+		    IWX_POWER_FLAGS_POWER_MANAGEMENT_ENA_MSK);
+		mcmd.rx_data_timeout = htole32(pmgt->rxtimeout * 1024);
+		mcmd.tx_data_timeout = htole32(pmgt->txtimeout * 1024);
+		if (skip_dtim != 0) {
+			mcmd.flags |= htole16(IWX_POWER_FLAGS_SKIP_OVER_DTIM_MSK);
+			mcmd.skip_dtim_periods = skip_dtim + 1;
+		}
+	}
+
+	err = iwx_send_cmd_pdu(sc, IWX_MAC_PM_POWER_TABLE, cmd_flags,
+	    sizeof(mcmd), &mcmd);
+	if (err != 0)
+		return err;
+
+	return iwx_update_beacon_abort(sc, in, !!(mcmd.flags &
+	    htole16(IWX_POWER_FLAGS_POWER_MANAGEMENT_ENA_MSK)));
+}
+
+int
 iwx_enable_beacon_filter(struct iwx_softc *sc, struct iwx_node *in)
 {
 	struct iwx_beacon_filter_cmd cmd = {
@@ -8669,11 +8766,13 @@ iwx_run(struct iwx_softc *sc)
 		return err;
 	}
 
-	err = iwx_power_update_device(sc);
-	if (err) {
-		printf("%s: could not send power command (error %d)\n",
-		    DEVNAME(sc), err);
-		return err;
+	if (ic->ic_flags & IEEE80211_F_PMGTON) {
+		err = iwx_set_pslevel(sc, 0, 3, 1);
+		if (err) {
+			printf("%s: could not send power command (error %d)\n",
+			    DEVNAME(sc), err);
+			return err;
+		}
 	}
 #ifdef notyet
 	/*
@@ -8691,13 +8790,6 @@ iwx_run(struct iwx_softc *sc)
 	if (ic->ic_opmode == IEEE80211_M_MONITOR)
 		return 0;
 
-	err = iwx_power_mac_update_mode(sc, in);
-	if (err) {
-		printf("%s: could not update MAC power (error %d)\n",
-		    DEVNAME(sc), err);
-		return err;
-	}
-
 	/* Start at lowest available bit-rate. Firmware will raise. */
 	in->in_ni.ni_txrate = 0;
 	in->in_ni.ni_txmcs = 0;
@@ -9578,7 +9670,7 @@ iwx_init_hw(struct iwx_softc *sc)
 			goto err;
 	}
 
-	err = iwx_power_update_device(sc);
+	err = iwx_set_pslevel(sc, 0, 0, 0);
 	if (err) {
 		printf("%s: could not send power command (error %d)\n",
 		    DEVNAME(sc), err);
@@ -9932,6 +10024,7 @@ int
 iwx_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 {
 	struct iwx_softc *sc = ifp->if_softc;
+	struct ieee80211com *ic = &sc->sc_ic;
 	int s, err = 0, generation = sc->sc_generation;
 
 	/*
@@ -9964,6 +10057,21 @@ iwx_ioctl(struct ifnet *ifp, u_long cmd,
 		}
 		break;
 
+	case SIOCS80211POWER:
+		err = ieee80211_ioctl(ifp, cmd, data);
+		if (err != ENETRESET)
+			break;
+		if (ic->ic_state == IEEE80211_S_RUN) {
+			if (ic->ic_flags & IEEE80211_F_PMGTON)
+				err = iwx_set_pslevel(sc, 0, 3, 0);
+			else	/* back to CAM */
+				err = iwx_set_pslevel(sc, 0, 0, 0);
+		} else {
+			/* Defer until transition to IEEE80211_S_RUN. */
+			err = 0;
+		}
+		break;
+
 	default:
 		err = ieee80211_ioctl(ifp, cmd, data);
 	}
@@ -11848,6 +11956,7 @@ iwx_attach(struct device *parent, struct
 	ic->ic_caps =
 	    IEEE80211_C_QOS | IEEE80211_C_TX_AMPDU | /* A-MPDU */
 	    IEEE80211_C_ADDBA_OFFLOAD | /* device sends ADDBA/DELBA frames */
+	    IEEE80211_C_PMGT |		/* power management */
 	    IEEE80211_C_WEP |		/* WEP */
 	    IEEE80211_C_RSN |		/* WPA/RSN */
 	    IEEE80211_C_SCANALL |	/* device scans all channels at once */
Index: sys/dev/pci/if_iwxreg.h
===================================================================
RCS file: /home/cvs/src/sys/dev/pci/if_iwxreg.h,v
diff -u -p -r1.58 if_iwxreg.h
--- sys/dev/pci/if_iwxreg.h	1 Dec 2025 16:44:13 -0000	1.58
+++ sys/dev/pci/if_iwxreg.h	30 Jan 2026 23:52:35 -0000
@@ -5096,6 +5096,42 @@ struct iwx_mac_power_cmd {
 #define IWX_DEFAULT_PS_TX_DATA_TIMEOUT      (100 * 1000)
 #define IWX_DEFAULT_PS_RX_DATA_TIMEOUT      (100 * 1000)
 
+#define IWX_NDTIMRANGES		3
+#define IWX_NPOWERLEVELS	6
+static const struct iwx_pmgt {
+	uint32_t	rxtimeout;
+	uint32_t	txtimeout;
+	int		skip_dtim;
+} iwx_pmgt[IWX_NDTIMRANGES][IWX_NPOWERLEVELS] = {
+	/* DTIM <= 2 */
+	{
+	{   0,   0, 0 },	/* CAM */
+	{ 200, 500, 0 },	/* PS level 1 */
+	{ 200, 300, 0 },	/* PS level 2 */
+	{  50, 100, 0 },	/* PS level 3 */
+	{  50,  25, 1 },	/* PS level 4 */
+	{  25,  25, 2 }		/* PS level 5 */
+	},
+	/* 3 <= DTIM <= 10 */
+	{
+	{   0,   0, 0 },	/* CAM */
+	{ 200, 500, 0 },	/* PS level 1 */
+	{ 200, 300, 0 },	/* PS level 2 */
+	{  50, 100, 0 },	/* PS level 3 */
+	{  50,  25, 1 },	/* PS level 4 */
+	{  25,  25, 2 }		/* PS level 5 */
+	},
+	/* DTIM >= 11 */
+	{
+	{   0,   0, 0 },	/* CAM */
+	{ 200, 500, 0 },	/* PS level 1 */
+	{ 200, 300, 0 },	/* PS level 2 */
+	{  50, 100, 0 },	/* PS level 3 */
+	{  50,  25, 0 },	/* PS level 4 */
+	{  25,  25, 0 }		/* PS level 5 */
+	}
+};
+
 /*
  * struct iwx_uapsd_misbehaving_ap_notif - FW sends this notification when
  * associated AP is identified as improperly implementing uAPSD protocol.

-- 
wbr, Kirill