diff --git a/drivers/net/ipa/gsi.c b/drivers/net/ipa/gsi.c
index a2fcdb1abdb96..5f9e9fb501e7f 100644
--- a/drivers/net/ipa/gsi.c
+++ b/drivers/net/ipa/gsi.c
@@ -1171,18 +1171,23 @@ static void gsi_isr_gp_int1(struct gsi *gsi)
 	u32 result;
 	u32 val;
 
-	/* This interrupt is used to handle completions of the two GENERIC
-	 * GSI commands.  We use these to allocate and halt channels on
-	 * the modem's behalf due to a hardware quirk on IPA v4.2.  Once
-	 * allocated, the modem "owns" these channels, and as a result we
-	 * have no way of knowing the channel's state at any given time.
+	/* This interrupt is used to handle completions of GENERIC GSI
+	 * commands.  We use these to allocate and halt channels on the
+	 * modem's behalf due to a hardware quirk on IPA v4.2.  The modem
+	 * "owns" channels even when the AP allocates them, and have no
+	 * way of knowing whether a modem channel's state has been changed.
+	 *
+	 * We also use GENERIC commands to enable/disable channel flow
+	 * control for IPA v4.2+.
 	 *
 	 * It is recommended that we halt the modem channels we allocated
 	 * when shutting down, but it's possible the channel isn't running
 	 * at the time we issue the HALT command.  We'll get an error in
 	 * that case, but it's harmless (the channel is already halted).
+	 * Similarly, we could get an error back when updating flow control
+	 * on a channel because it's not in the proper state.
 	 *
-	 * For this reason, we silently ignore a CHANNEL_NOT_RUNNING error
+	 * In either case, we silently ignore a CHANNEL_NOT_RUNNING error
 	 * if we receive it.
 	 */
 	val = ioread32(gsi->virt + GSI_CNTXT_SCRATCH_0_OFFSET);
@@ -1648,6 +1653,10 @@ static void gsi_channel_teardown_one(struct gsi *gsi, u32 channel_id)
 	gsi_evt_ring_de_alloc_command(gsi, evt_ring_id);
 }
 
+/* We use generic commands only to operate on modem channels.  We don't have
+ * the ability to determine channel state for a modem channel, so we simply
+ * issue the command and wait for it to complete.
+ */
 static int gsi_generic_command(struct gsi *gsi, u32 channel_id,
 			       enum gsi_generic_cmd_opcode opcode)
 {
@@ -1655,12 +1664,14 @@ static int gsi_generic_command(struct gsi *gsi, u32 channel_id,
 	bool timeout;
 	u32 val;
 
-	/* The error global interrupt type is always enabled (until we
-	 * teardown), so we won't change that.  A generic EE command
-	 * completes with a GSI global interrupt of type GP_INT1.  We
-	 * only perform one generic command at a time (to allocate or
-	 * halt a modem channel) and only from this function.  So we
-	 * enable the GP_INT1 IRQ type here while we're expecting it.
+	/* The error global interrupt type is always enabled (until we tear
+	 * down), so we will keep it enabled.
+	 *
+	 * A generic EE command completes with a GSI global interrupt of
+	 * type GP_INT1.  We only perform one generic command at a time
+	 * (to allocate, halt, or enable/disable flow control on a modem
+	 * channel), and only from this function.  So we enable the GP_INT1
+	 * IRQ type here, and disable it again after the command completes.
 	 */
 	val = BIT(ERROR_INT) | BIT(GP_INT1);
 	iowrite32(val, gsi->virt + GSI_CNTXT_GLOB_IRQ_EN_OFFSET);
@@ -1710,6 +1721,23 @@ static void gsi_modem_channel_halt(struct gsi *gsi, u32 channel_id)
 			ret, channel_id);
 }
 
+/* Enable or disable flow control for a modem GSI TX channel (IPA v4.2+) */
+void
+gsi_modem_channel_flow_control(struct gsi *gsi, u32 channel_id, bool enable)
+{
+	u32 command;
+	int ret;
+
+	command = enable ? GSI_GENERIC_ENABLE_FLOW_CONTROL
+			 : GSI_GENERIC_DISABLE_FLOW_CONTROL;
+
+	ret = gsi_generic_command(gsi, channel_id, command);
+	if (ret)
+		dev_err(gsi->dev,
+			"error %d %sabling mode channel %u flow control\n",
+			ret, enable ? "en" : "dis", channel_id);
+}
+
 /* Setup function for channels */
 static int gsi_channel_setup(struct gsi *gsi)
 {
diff --git a/drivers/net/ipa/gsi.h b/drivers/net/ipa/gsi.h
index 88b80dc3db79f..41b3ab14c5124 100644
--- a/drivers/net/ipa/gsi.h
+++ b/drivers/net/ipa/gsi.h
@@ -101,6 +101,7 @@ enum gsi_channel_state {
 	GSI_CHANNEL_STATE_STARTED		= 0x2,
 	GSI_CHANNEL_STATE_STOPPED		= 0x3,
 	GSI_CHANNEL_STATE_STOP_IN_PROC		= 0x4,
+	GSI_CHANNEL_STATE_FLOW_CONTROLLED	= 0x5,	/* IPA v4.2+ */
 	GSI_CHANNEL_STATE_ERROR			= 0xf,
 };
 
@@ -218,6 +219,15 @@ int gsi_channel_start(struct gsi *gsi, u32 channel_id);
  */
 int gsi_channel_stop(struct gsi *gsi, u32 channel_id);
 
+/**
+ * gsi_modem_channel_flow_control() - Set channel flow control state (IPA v4.2+)
+ * @gsi:	GSI pointer returned by gsi_setup()
+ * @channel_id:	Modem TX channel to control
+ * @enable:	Whether to enable flow control (i.e., prevent flow)
+ */
+void gsi_modem_channel_flow_control(struct gsi *gsi, u32 channel_id,
+				    bool enable);
+
 /**
  * gsi_channel_reset() - Reset an allocated GSI channel
  * @gsi:	GSI pointer
diff --git a/drivers/net/ipa/gsi_reg.h b/drivers/net/ipa/gsi_reg.h
index bf9593d9eaead..4ab23998b3485 100644
--- a/drivers/net/ipa/gsi_reg.h
+++ b/drivers/net/ipa/gsi_reg.h
@@ -318,6 +318,8 @@ enum gsi_evt_cmd_opcode {
 enum gsi_generic_cmd_opcode {
 	GSI_GENERIC_HALT_CHANNEL		= 0x1,
 	GSI_GENERIC_ALLOCATE_CHANNEL		= 0x2,
+	GSI_GENERIC_ENABLE_FLOW_CONTROL		= 0x3,	/* IPA v4.2+ */
+	GSI_GENERIC_DISABLE_FLOW_CONTROL	= 0x4,	/* IPA v4.2+ */
 };
 
 /* The next register is present for IPA v3.5.1 and above */
diff --git a/drivers/net/ipa/ipa_endpoint.c b/drivers/net/ipa/ipa_endpoint.c
index ef790fd0ab56a..d89347a88e50b 100644
--- a/drivers/net/ipa/ipa_endpoint.c
+++ b/drivers/net/ipa/ipa_endpoint.c
@@ -237,7 +237,8 @@ static struct gsi_trans *ipa_endpoint_trans_alloc(struct ipa_endpoint *endpoint,
 }
 
 /* suspend_delay represents suspend for RX, delay for TX endpoints.
- * Note that suspend is not supported starting with IPA v4.0.
+ * Note that suspend is not supported starting with IPA v4.0, and
+ * delay mode should not be used starting with IPA v4.2.
  */
 static bool
 ipa_endpoint_init_ctrl(struct ipa_endpoint *endpoint, bool suspend_delay)
@@ -248,11 +249,8 @@ ipa_endpoint_init_ctrl(struct ipa_endpoint *endpoint, bool suspend_delay)
 	u32 mask;
 	u32 val;
 
-	/* Suspend is not supported for IPA v4.0+.  Delay doesn't work
-	 * correctly on IPA v4.2.
-	 */
 	if (endpoint->toward_ipa)
-		WARN_ON(ipa->version == IPA_VERSION_4_2);
+		WARN_ON(ipa->version >= IPA_VERSION_4_2);
 	else
 		WARN_ON(ipa->version >= IPA_VERSION_4_0);
 
@@ -270,15 +268,15 @@ ipa_endpoint_init_ctrl(struct ipa_endpoint *endpoint, bool suspend_delay)
 	return state;
 }
 
-/* We currently don't care what the previous state was for delay mode */
+/* We don't care what the previous state was for delay mode */
 static void
 ipa_endpoint_program_delay(struct ipa_endpoint *endpoint, bool enable)
 {
+	/* Delay mode should not be used for IPA v4.2+ */
+	WARN_ON(endpoint->ipa->version >= IPA_VERSION_4_2);
 	WARN_ON(!endpoint->toward_ipa);
 
-	/* Delay mode doesn't work properly for IPA v4.2 */
-	if (endpoint->ipa->version != IPA_VERSION_4_2)
-		(void)ipa_endpoint_init_ctrl(endpoint, enable);
+	(void)ipa_endpoint_init_ctrl(endpoint, enable);
 }
 
 static bool ipa_endpoint_aggr_active(struct ipa_endpoint *endpoint)
@@ -355,26 +353,29 @@ ipa_endpoint_program_suspend(struct ipa_endpoint *endpoint, bool enable)
 	return suspended;
 }
 
-/* Enable or disable delay or suspend mode on all modem endpoints */
+/* Put all modem RX endpoints into suspend mode, and stop transmission
+ * on all modem TX endpoints.  Prior to IPA v4.2, endpoint DELAY mode is
+ * used for TX endpoints; starting with IPA v4.2 we use GSI channel flow
+ * control instead.
+ */
 void ipa_endpoint_modem_pause_all(struct ipa *ipa, bool enable)
 {
 	u32 endpoint_id;
 
-	/* DELAY mode doesn't work correctly on IPA v4.2 */
-	if (ipa->version == IPA_VERSION_4_2)
-		return;
-
 	for (endpoint_id = 0; endpoint_id < IPA_ENDPOINT_MAX; endpoint_id++) {
 		struct ipa_endpoint *endpoint = &ipa->endpoint[endpoint_id];
 
 		if (endpoint->ee_id != GSI_EE_MODEM)
 			continue;
 
-		/* Set TX delay mode or RX suspend mode */
-		if (endpoint->toward_ipa)
+		if (!endpoint->toward_ipa)
+			(void)ipa_endpoint_program_suspend(endpoint, enable);
+		else if (ipa->version < IPA_VERSION_4_2)
 			ipa_endpoint_program_delay(endpoint, enable);
 		else
-			(void)ipa_endpoint_program_suspend(endpoint, enable);
+			gsi_modem_channel_flow_control(&ipa->gsi,
+						       endpoint->channel_id,
+						       enable);
 	}
 }
 
@@ -1519,10 +1520,19 @@ static void ipa_endpoint_reset(struct ipa_endpoint *endpoint)
 
 static void ipa_endpoint_program(struct ipa_endpoint *endpoint)
 {
-	if (endpoint->toward_ipa)
-		ipa_endpoint_program_delay(endpoint, false);
-	else
+	if (endpoint->toward_ipa) {
+		/* Newer versions of IPA use GSI channel flow control
+		 * instead of endpoint DELAY mode to prevent sending data.
+		 * Flow control is disabled for newly-allocated channels,
+		 * and we can assume flow control is not (ever) enabled
+		 * for AP TX channels.
+		 */
+		if (endpoint->ipa->version < IPA_VERSION_4_2)
+			ipa_endpoint_program_delay(endpoint, false);
+	} else {
+		/* Ensure suspend mode is off on all AP RX endpoints */
 		(void)ipa_endpoint_program_suspend(endpoint, false);
+	}
 	ipa_endpoint_init_cfg(endpoint);
 	ipa_endpoint_init_nat(endpoint);
 	ipa_endpoint_init_hdr(endpoint);
