diff --git a/tools/testing/selftests/net/gro.c b/tools/testing/selftests/net/gro.c
index 353e1e867fbb..74ab06953c38 100644
--- a/tools/testing/selftests/net/gro.c
+++ b/tools/testing/selftests/net/gro.c
@@ -617,6 +617,120 @@ static void add_ipv6_exthdr(void *buf, void *optpkt, __u8 exthdr_type, char *ext
 	iph->payload_len = htons(ntohs(iph->payload_len) + MIN_EXTHDR_SIZE);
 }
 
+static void fix_ip4_checksum(struct iphdr *iph)
+{
+	iph->check = 0;
+	iph->check = checksum_fold(iph, sizeof(struct iphdr), 0);
+}
+
+static void send_flush_id_case(int fd, struct sockaddr_ll *daddr, int tcase)
+{
+	bool send_three = false;
+	static char buf1[MAX_HDR_LEN + PAYLOAD_LEN];
+	static char buf2[MAX_HDR_LEN + PAYLOAD_LEN];
+	static char buf3[MAX_HDR_LEN + PAYLOAD_LEN];
+
+	create_packet(buf1, 0, 0, PAYLOAD_LEN, 0);
+	create_packet(buf2, PAYLOAD_LEN, 0, PAYLOAD_LEN, 0);
+	create_packet(buf3, PAYLOAD_LEN * 2, 0, PAYLOAD_LEN, 0);
+
+	struct iphdr *iph1 = (struct iphdr *)(buf1 + ETH_HLEN);
+	struct iphdr *iph2 = (struct iphdr *)(buf2 + ETH_HLEN);
+	struct iphdr *iph3 = (struct iphdr *)(buf3 + ETH_HLEN);
+
+	switch (tcase) {
+	case 0: /* DF=1, Incrementing - should coalesce */
+		iph1->frag_off |= htons(IP_DF);
+		iph1->id = htons(8);
+		fix_ip4_checksum(iph1);
+
+		iph2->frag_off |= htons(IP_DF);
+		iph2->id = htons(9);
+		fix_ip4_checksum(iph2);
+		break;
+
+	case 1: /* DF=1, Fixed - should coalesce */
+		iph1->frag_off |= htons(IP_DF);
+		iph1->id = htons(8);
+		fix_ip4_checksum(iph1);
+
+		iph2->frag_off |= htons(IP_DF);
+		iph2->id = htons(8);
+		fix_ip4_checksum(iph2);
+		break;
+
+	case 2: /* DF=0, Incrementing - should coalesce */
+		iph1->frag_off &= ~htons(IP_DF);
+		iph1->id = htons(8);
+		fix_ip4_checksum(iph1);
+
+		iph2->frag_off &= ~htons(IP_DF);
+		iph2->id = htons(9);
+		fix_ip4_checksum(iph2);
+		break;
+
+	case 3: /* DF=0, Fixed - should not coalesce */
+		iph1->frag_off &= ~htons(IP_DF);
+		iph1->id = htons(8);
+		fix_ip4_checksum(iph1);
+
+		iph2->frag_off &= ~htons(IP_DF);
+		iph2->id = htons(8);
+		fix_ip4_checksum(iph2);
+		break;
+
+	case 4: /* DF=1, two packets incrementing, and one fixed - should
+		 * coalesce only the first two packets
+		 */
+		iph1->frag_off |= htons(IP_DF);
+		iph1->id = htons(8);
+		fix_ip4_checksum(iph1);
+
+		iph2->frag_off |= htons(IP_DF);
+		iph2->id = htons(9);
+		fix_ip4_checksum(iph2);
+
+		iph3->frag_off |= htons(IP_DF);
+		iph3->id = htons(9);
+		fix_ip4_checksum(iph3);
+		send_three = true;
+		break;
+
+	case 5: /* DF=1, two packets fixed, and one incrementing - should
+		 * coalesce only the first two packets
+		 */
+		iph1->frag_off |= htons(IP_DF);
+		iph1->id = htons(8);
+		fix_ip4_checksum(iph1);
+
+		iph2->frag_off |= htons(IP_DF);
+		iph2->id = htons(8);
+		fix_ip4_checksum(iph2);
+
+		iph3->frag_off |= htons(IP_DF);
+		iph3->id = htons(9);
+		fix_ip4_checksum(iph3);
+		send_three = true;
+		break;
+	}
+
+	write_packet(fd, buf1, total_hdr_len + PAYLOAD_LEN, daddr);
+	write_packet(fd, buf2, total_hdr_len + PAYLOAD_LEN, daddr);
+
+	if (send_three)
+		write_packet(fd, buf3, total_hdr_len + PAYLOAD_LEN, daddr);
+}
+
+static void test_flush_id(int fd, struct sockaddr_ll *daddr, char *fin_pkt)
+{
+	for (int i = 0; i < 6; i++) {
+		sleep(1);
+		send_flush_id_case(fd, daddr, i);
+		sleep(1);
+		write_packet(fd, fin_pkt, total_hdr_len, daddr);
+	}
+}
+
 static void send_ipv6_exthdr(int fd, struct sockaddr_ll *daddr, char *ext_data1, char *ext_data2)
 {
 	static char buf[MAX_HDR_LEN + PAYLOAD_LEN];
@@ -935,6 +1049,8 @@ static void gro_sender(void)
 			send_fragment4(txfd, &daddr);
 			sleep(1);
 			write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
+
+			test_flush_id(txfd, &daddr, fin_pkt);
 		} else if (proto == PF_INET6) {
 			sleep(1);
 			send_fragment6(txfd, &daddr);
@@ -1061,6 +1177,34 @@ static void gro_receiver(void)
 
 			printf("fragmented ip4 doesn't coalesce: ");
 			check_recv_pkts(rxfd, correct_payload, 2);
+
+			/* is_atomic checks */
+			printf("DF=1, Incrementing - should coalesce: ");
+			correct_payload[0] = PAYLOAD_LEN * 2;
+			check_recv_pkts(rxfd, correct_payload, 1);
+
+			printf("DF=1, Fixed - should coalesce: ");
+			correct_payload[0] = PAYLOAD_LEN * 2;
+			check_recv_pkts(rxfd, correct_payload, 1);
+
+			printf("DF=0, Incrementing - should coalesce: ");
+			correct_payload[0] = PAYLOAD_LEN * 2;
+			check_recv_pkts(rxfd, correct_payload, 1);
+
+			printf("DF=0, Fixed - should not coalesce: ");
+			correct_payload[0] = PAYLOAD_LEN;
+			correct_payload[1] = PAYLOAD_LEN;
+			check_recv_pkts(rxfd, correct_payload, 2);
+
+			printf("DF=1, 2 Incrementing and one fixed - should coalesce only first 2 packets: ");
+			correct_payload[0] = PAYLOAD_LEN * 2;
+			correct_payload[1] = PAYLOAD_LEN;
+			check_recv_pkts(rxfd, correct_payload, 2);
+
+			printf("DF=1, 2 Fixed and one incrementing - should coalesce only first 2 packets: ");
+			correct_payload[0] = PAYLOAD_LEN * 2;
+			correct_payload[1] = PAYLOAD_LEN;
+			check_recv_pkts(rxfd, correct_payload, 2);
 		} else if (proto == PF_INET6) {
 			/* GRO doesn't check for ipv6 hop limit when flushing.
 			 * Hence no corresponding test to the ipv4 case.
