Index: sys/dev/nand/nandemulator.c
===================================================================
RCS file: /cvsroot/src/sys/dev/nand/nandemulator.c,v
retrieving revision 1.7
diff -p -u -r1.7 nandemulator.c
--- sys/dev/nand/nandemulator.c	20 Aug 2015 14:40:18 -0000	1.7
+++ sys/dev/nand/nandemulator.c	4 Feb 2019 22:09:11 -0000
@@ -388,9 +388,13 @@ nandemulator_command(device_t self, uint
 		break;
 	case ONFI_PAGE_PROGRAM:
 		sc->sc_register_writable = true;
+		// XXXMRG or break?
+		/* FALLTHROUGH */
 	case ONFI_READ:
 	case ONFI_BLOCK_ERASE:
 		sc->sc_address_counter = 0;
+		// XXXMRG or break?
+		/* FALLTHROUGH */
 	case ONFI_READ_ID:
 	case ONFI_READ_PARAMETER_PAGE:
 		sc->sc_io_len = 0;
Index: sys/dev/pci/agp_intel.c
===================================================================
RCS file: /cvsroot/src/sys/dev/pci/agp_intel.c,v
retrieving revision 1.37
diff -p -u -r1.37 agp_intel.c
--- sys/dev/pci/agp_intel.c	4 Apr 2011 20:37:56 -0000	1.37
+++ sys/dev/pci/agp_intel.c	4 Feb 2019 22:09:11 -0000
@@ -209,6 +209,8 @@ agp_intel_init(struct agp_softc *sc)
 	case CHIP_I443:
 		pci_conf_write(sc->as_pc, sc->as_tag, AGP_INTEL_AGPCTRL,
 		    AGPCTRL_AGPRSE | AGPCTRL_GTLB);
+		break;
+		// XXXMRG break or fallthru???
 
 	default:
 		pci_conf_write(sc->as_pc, sc->as_tag, AGP_INTEL_AGPCTRL,
Index: sys/dev/pci/siside.c
===================================================================
RCS file: /cvsroot/src/sys/dev/pci/siside.c,v
retrieving revision 1.37
diff -p -u -r1.37 siside.c
--- sys/dev/pci/siside.c	23 Jun 2018 06:45:51 -0000	1.37
+++ sys/dev/pci/siside.c	4 Feb 2019 22:09:11 -0000
@@ -451,6 +451,8 @@ sis_setup_channel(struct ata_channel *ch
 				sis_tim |=
 				    sis_udma100new_tim[drvp->UDMA_mode] <<
 				    SIS_TIM100_UDMA_TIME_OFF(drive);
+				// XXXMRG -- or break???
+				/* FALLTHROUGH */
 			case SIS_TYPE_133OLD:
 				sis_tim |=
 				    sis_udma133old_tim[drvp->UDMA_mode] <<
Index: sys/dev/scsipi/scsipi_base.c
===================================================================
RCS file: /cvsroot/src/sys/dev/scsipi/scsipi_base.c,v
retrieving revision 1.180
diff -p -u -r1.180 scsipi_base.c
--- sys/dev/scsipi/scsipi_base.c	24 Nov 2018 18:15:23 -0000	1.180
+++ sys/dev/scsipi/scsipi_base.c	4 Feb 2019 22:09:11 -0000
@@ -947,6 +947,8 @@ scsipi_interpret_sense(struct scsipi_xfe
 				 */
 				xs->resid = 0;	/* not short read */
 			}
+			// XXXMRG or break???
+			/* FALLTHROUGH */
 		case SKEY_EQUAL:
 			error = 0;
 			break;
Index: sys/dev/wscons/wskbd.c
===================================================================
RCS file: /cvsroot/src/sys/dev/wscons/wskbd.c,v
retrieving revision 1.142
diff -p -u -r1.142 wskbd.c
--- sys/dev/wscons/wskbd.c	18 Sep 2018 06:19:28 -0000	1.142
+++ sys/dev/wscons/wskbd.c	4 Feb 2019 22:09:11 -0000
@@ -1548,6 +1548,8 @@ internal_command(struct wskbd_softc *sc,
 				return (0);
 			}
 		}
+		// XXXMRG or break???
+		break;
 
 	case KS_Cmd_ScrollSlowUp:
 	case KS_Cmd_ScrollSlowDown:
@@ -1567,6 +1569,8 @@ internal_command(struct wskbd_softc *sc,
 				return (0);
 			}
 		}
+		// XXXMRG or break???
+		break;
 #endif
 
 	case KS_Cmd:
Index: tests/lib/libc/sys/t_ptrace_x86_wait.h
===================================================================
RCS file: /cvsroot/src/tests/lib/libc/sys/t_ptrace_x86_wait.h,v
retrieving revision 1.7
diff -p -u -r1.7 t_ptrace_x86_wait.h
--- tests/lib/libc/sys/t_ptrace_x86_wait.h	26 May 2018 20:27:48 -0000	1.7
+++ tests/lib/libc/sys/t_ptrace_x86_wait.h	4 Feb 2019 22:09:11 -0000
@@ -405,14 +405,20 @@ dbregs_trap_variable(int reg, int cond, 
 		dr7.bits.global_dr0_breakpoint = 1;
 		dr7.bits.condition_dr0 = cond;
 		dr7.bits.len_dr0 = len;
+		// XXXMRG or break???
+		break;
 	case 1:
 		dr7.bits.global_dr1_breakpoint = 1;
 		dr7.bits.condition_dr1 = cond;
 		dr7.bits.len_dr1 = len;
+		// XXXMRG or break???
+		break;
 	case 2:
 		dr7.bits.global_dr2_breakpoint = 1;
 		dr7.bits.condition_dr2 = cond;
 		dr7.bits.len_dr2 = len;
+		// XXXMRG or break???
+		break;
 	case 3:
 		dr7.bits.global_dr3_breakpoint = 1;
 		dr7.bits.condition_dr3 = cond;