Index: sys/arch/arm/rockchip/rk_platform.c
===================================================================
RCS file: /cvsroot/src/sys/arch/arm/rockchip/rk_platform.c,v
retrieving revision 1.12
diff -p -u -r1.12 rk_platform.c
--- sys/arch/arm/rockchip/rk_platform.c	24 Apr 2021 23:36:28 -0000	1.12
+++ sys/arch/arm/rockchip/rk_platform.c	22 Jun 2021 23:27:43 -0000
@@ -39,6 +39,8 @@ __KERNEL_RCSID(0, "$NetBSD: rk_platform.
 #include <sys/device.h>
 #include <sys/termios.h>
 
+#include <prop/proplib.h>
+
 #include <dev/fdt/fdtvar.h>
 #include <arm/fdt/arm_fdtvar.h>
 
@@ -70,6 +72,17 @@ rk_platform_init_attach_args(struct fdt_
 static void
 rk_platform_device_register(device_t self, void *aux)
 {
+	prop_dictionary_t dict = device_properties(self);
+
+	if (device_is_a(self, "ahcisata")) {
+		/*
+		 * Marvel 9230 AHCI SATA controllers take between 1213 and 1216
+		 * milliseconds to reset, exceeding the AHCI spec of 1000.
+		 */
+		if (!prop_dictionary_set_uint32(dict, "ahci-reset-ms", 2000))
+			printf("%s: Failed to set \"ahci-reset-ms\" property"
+			       " on ahcisata\n", __func__);
+	}
 }
 
 static void
Index: sys/dev/ic/ahcisata_core.c
===================================================================
RCS file: /cvsroot/src/sys/dev/ic/ahcisata_core.c,v
retrieving revision 1.98
diff -p -u -r1.98 ahcisata_core.c
--- sys/dev/ic/ahcisata_core.c	24 Apr 2021 23:36:55 -0000	1.98
+++ sys/dev/ic/ahcisata_core.c	22 Jun 2021 23:27:43 -0000
@@ -144,19 +144,35 @@ static int
 ahci_reset(struct ahci_softc *sc)
 {
 	int i;
+	uint32_t ctrl;
+	uint32_t timeout = 1000;
+	prop_dictionary_t dict;
 
 	/* reset controller */
-	AHCI_WRITE(sc, AHCI_GHC, AHCI_GHC_HR);
+	ctrl = AHCI_READ(sc, AHCI_GHC);
+	if ((ctrl & AHCI_GHC_HR) == 0) {
+		AHCI_WRITE(sc, AHCI_GHC, ctrl | AHCI_GHC_HR);
+	}
+
+	/* some systems (rockchip rk3399) need extra reset time for ahcisata. */
+	dict = device_properties(sc->sc_atac.atac_dev);
+	if (dict)
+		prop_dictionary_get_uint32(dict, "ahci-reset-ms", &timeout);
+
 	/* wait up to 1s for reset to complete */
-	for (i = 0; i < 1000; i++) {
+	for (i = 0; i < timeout; i++) {
 		delay(1000);
 		if ((AHCI_READ(sc, AHCI_GHC) & AHCI_GHC_HR) == 0)
 			break;
 	}
-	if ((AHCI_READ(sc, AHCI_GHC) & AHCI_GHC_HR)) {
-		aprint_error("%s: reset failed\n", AHCINAME(sc));
+	if ((AHCI_READ(sc, AHCI_GHC) & AHCI_GHC_HR) != 0) {
+		aprint_error_dev(sc->sc_atac.atac_dev, "reset failed\n");
 		return -1;
 	}
+	if (i > 1000) {
+		aprint_normal_dev(sc->sc_atac.atac_dev,
+		    "reset took %d milliseconds\n", i);
+	}
 	/* enable ahci mode */
 	ahci_enable(sc);