Do pass removing some write-only variables from the kernel.

This reduces noise when kernel is compiled by newer GCC versions,
such as one used by external toolchain ports.

Reviewed by: kib, andrew(sys/arm and sys/arm64), emaste(partial), erj(partial)
Reviewed by: jhb (sys/dev/pci/* sys/kern/vfs_aio.c and sys/kern/kern_synch.c)
Differential Revision: https://reviews.freebsd.org/D10385

28 files changed, 18 insertions, 107 deletions

diff --git a/sys/dev/al_eth/al_eth.c b/sys/dev/al_eth/al_eth.c
index 79523fd189c3..211e55c40fde 100644
--- a/sys/dev/al_eth/al_eth.c
+++ b/sys/dev/al_eth/al_eth.c
@@ -272,7 +272,6 @@ al_probe(device_t dev)
 static int
 al_attach(device_t dev)
 {
-	struct al_eth_lm_context *lm_context;
 	struct al_eth_adapter *adapter;
 	struct sysctl_oid_list *child;
 	struct sysctl_ctx_list *ctx;
@@ -305,8 +304,6 @@ al_attach(device_t dev)
 
 	g_adapters[g_adapters_count] = adapter;
 
-	lm_context = &adapter->lm_context;
-
 	bar_udma = PCIR_BAR(AL_ETH_UDMA_BAR);
 	adapter->udma_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
 	    &bar_udma, RF_ACTIVE);
diff --git a/sys/dev/axgbe/xgbe-drv.c b/sys/dev/axgbe/xgbe-drv.c
index 32a6cfe239c1..81f8f30b927a 100644
--- a/sys/dev/axgbe/xgbe-drv.c
+++ b/sys/dev/axgbe/xgbe-drv.c
@@ -954,7 +954,7 @@ static int xgbe_rx_poll(struct xgbe_channel *channel, int budget)
 	struct xgbe_packet_data *packet;
 	struct ifnet *ifp = pdata->netdev;
 	struct mbuf *m;
-	unsigned int incomplete, context_next, context;
+	unsigned int incomplete, context_next;
 	unsigned int received = 0;
 	int packet_count = 0;
 
@@ -992,9 +992,6 @@ read_again:
 		context_next = XGMAC_GET_BITS(packet->attributes,
 					      RX_PACKET_ATTRIBUTES,
 					      CONTEXT_NEXT);
-		context = XGMAC_GET_BITS(packet->attributes,
-					 RX_PACKET_ATTRIBUTES,
-					 CONTEXT);
 
 		/* Earlier error, just drain the remaining data */
 		if (incomplete || context_next) {
diff --git a/sys/dev/axgbe/xgbe-mdio.c b/sys/dev/axgbe/xgbe-mdio.c
index 6967d54da521..850a58e04107 100644
--- a/sys/dev/axgbe/xgbe-mdio.c
+++ b/sys/dev/axgbe/xgbe-mdio.c
@@ -752,36 +752,30 @@ static void xgbe_an_init(struct xgbe_prv_data *pdata)
 
 static void xgbe_phy_adjust_link(struct xgbe_prv_data *pdata)
 {
-	int new_state = 0;
 
 	if (pdata->phy.link) {
 		/* Flow control support */
 		pdata->pause_autoneg = pdata->phy.pause_autoneg;
 
 		if (pdata->tx_pause != pdata->phy.tx_pause) {
-			new_state = 1;
 			pdata->hw_if.config_tx_flow_control(pdata);
 			pdata->tx_pause = pdata->phy.tx_pause;
 		}
 
 		if (pdata->rx_pause != pdata->phy.rx_pause) {
-			new_state = 1;
 			pdata->hw_if.config_rx_flow_control(pdata);
 			pdata->rx_pause = pdata->phy.rx_pause;
 		}
 
 		/* Speed support */
 		if (pdata->phy_speed != pdata->phy.speed) {
-			new_state = 1;
 			pdata->phy_speed = pdata->phy.speed;
 		}
 
 		if (pdata->phy_link != pdata->phy.link) {
-			new_state = 1;
 			pdata->phy_link = pdata->phy.link;
 		}
 	} else if (pdata->phy_link) {
-		new_state = 1;
 		pdata->phy_link = 0;
 		pdata->phy_speed = SPEED_UNKNOWN;
 	}
diff --git a/sys/dev/e1000/igb_txrx.c b/sys/dev/e1000/igb_txrx.c
index 8a56c64b6c18..1a2f7fbbd41b 100644
--- a/sys/dev/e1000/igb_txrx.c
+++ b/sys/dev/e1000/igb_txrx.c
@@ -237,7 +237,7 @@ igb_isc_txd_encap(void *arg, if_pkt_info_t pi)
 	int nsegs = pi->ipi_nsegs;
 	bus_dma_segment_t *segs = pi->ipi_segs;
 	union e1000_adv_tx_desc *txd = NULL;
-	int i, j, first, pidx_last;
+	int i, j, pidx_last;
 	u32 olinfo_status, cmd_type_len, txd_flags;
 	qidx_t ntxd;
 
@@ -249,7 +249,7 @@ igb_isc_txd_encap(void *arg, if_pkt_info_t pi)
 	if (pi->ipi_mflags & M_VLANTAG)
 		cmd_type_len |= E1000_ADVTXD_DCMD_VLE;
 
-	first = i = pi->ipi_pidx;
+	i = pi->ipi_pidx;
 	ntxd = scctx->isc_ntxd[0];
 	txd_flags = pi->ipi_flags & IPI_TX_INTR ? E1000_ADVTXD_DCMD_RS : 0;
 	/* Consume the first descriptor */
diff --git a/sys/dev/extres/clk/clk_bus.c b/sys/dev/extres/clk/clk_bus.c
index e475736a901c..e083ed0595d4 100644
--- a/sys/dev/extres/clk/clk_bus.c
+++ b/sys/dev/extres/clk/clk_bus.c
@@ -60,11 +60,9 @@ ofw_clkbus_probe(device_t dev)
 static int
 ofw_clkbus_attach(device_t dev)
 {
-	struct ofw_clkbus_softc *sc;
 	phandle_t node, child;
 	device_t cdev;
 
-	sc = device_get_softc(dev);
 	node  = ofw_bus_get_node(dev);
 	simplebus_init(dev, node);
 
diff --git a/sys/dev/extres/regulator/regulator_bus.c b/sys/dev/extres/regulator/regulator_bus.c
index 5e7f4c92d0e3..bac88904a543 100644
--- a/sys/dev/extres/regulator/regulator_bus.c
+++ b/sys/dev/extres/regulator/regulator_bus.c
@@ -58,10 +58,8 @@ ofw_regulator_bus_probe(device_t dev)
 static int
 ofw_regulator_bus_attach(device_t dev)
 {
-	struct ofw_regulator_bus_softc *sc;
 	phandle_t node, child;
 
-	sc = device_get_softc(dev);
 	node  = ofw_bus_get_node(dev);
 	simplebus_init(dev, node);
 
diff --git a/sys/dev/fdt/fdt_common.c b/sys/dev/fdt/fdt_common.c
index d163cac3e67b..be7dd218e5fb 100644
--- a/sys/dev/fdt/fdt_common.c
+++ b/sys/dev/fdt/fdt_common.c
@@ -155,7 +155,7 @@ fdt_get_range(phandle_t node, int range_id, u_long *base, u_long *size)
 	pcell_t ranges[FDT_RANGES_SIZE], *rangesptr;
 	pcell_t addr_cells, size_cells, par_addr_cells;
 	u_long par_bus_addr, pbase, psize;
-	int err, len, tuple_size, tuples;
+	int err, len;
 
 	if ((fdt_addrsize_cells(node, &addr_cells, &size_cells)) != 0)
 		return (ENXIO);
@@ -181,10 +181,6 @@ fdt_get_range(phandle_t node, int range_id, u_long *base, u_long *size)
 	if (OF_getprop(node, "ranges", ranges, sizeof(ranges)) <= 0)
 		return (EINVAL);
 
-	tuple_size = sizeof(pcell_t) * (addr_cells + par_addr_cells +
-	    size_cells);
-	tuples = len / tuple_size;
-
 	if (par_addr_cells > 2 || addr_cells > 2 || size_cells > 2)
 		return (ERANGE);
 
@@ -600,11 +596,9 @@ fdt_get_reserved_regions(struct mem_region *mr, int *mrcnt)
 	pcell_t reserve[FDT_REG_CELLS * FDT_MEM_REGIONS];
 	pcell_t *reservep;
 	phandle_t memory, root;
-	uint32_t memory_size;
 	int addr_cells, size_cells;
-	int i, max_size, res_len, rv, tuple_size, tuples;
+	int i, res_len, rv, tuple_size, tuples;
 
-	max_size = sizeof(reserve);
 	root = OF_finddevice("/");
 	memory = OF_finddevice("/memory");
 	if (memory == -1) {
@@ -634,7 +628,6 @@ fdt_get_reserved_regions(struct mem_region *mr, int *mrcnt)
 		goto out;
 	}
 
-	memory_size = 0;
 	tuples = res_len / tuple_size;
 	reservep = (pcell_t *)&reserve;
 	for (i = 0; i < tuples; i++) {
@@ -662,9 +655,8 @@ fdt_get_mem_regions(struct mem_region *mr, int *mrcnt, uint64_t *memsize)
 	phandle_t memory;
 	uint64_t memory_size;
 	int addr_cells, size_cells;
-	int i, max_size, reg_len, rv, tuple_size, tuples;
+	int i, reg_len, rv, tuple_size, tuples;
 
-	max_size = sizeof(reg);
 	memory = OF_finddevice("/memory");
 	if (memory == -1) {
 		rv = ENXIO;
diff --git a/sys/dev/mii/rdcphy.c b/sys/dev/mii/rdcphy.c
index c03cf550eec6..d7fa8ced4fdb 100644
--- a/sys/dev/mii/rdcphy.c
+++ b/sys/dev/mii/rdcphy.c
@@ -185,11 +185,9 @@ static void
 rdcphy_status(struct mii_softc *sc)
 {
 	struct mii_data *mii;
-	struct ifmedia_entry *ife;
 	int bmsr, bmcr, physts;
 
 	mii = sc->mii_pdata;
-	ife = mii->mii_media.ifm_cur;
 
 	mii->mii_media_status = IFM_AVALID;
 	mii->mii_media_active = IFM_ETHER;
diff --git a/sys/dev/mmc/host/dwmmc.c b/sys/dev/mmc/host/dwmmc.c
index cb374a0e240e..80e719686185 100644
--- a/sys/dev/mmc/host/dwmmc.c
+++ b/sys/dev/mmc/host/dwmmc.c
@@ -751,12 +751,10 @@ static int
 dma_prepare(struct dwmmc_softc *sc, struct mmc_command *cmd)
 {
 	struct mmc_data *data;
-	int len;
 	int err;
 	int reg;
 
 	data = cmd->data;
-	len = data->len;
 
 	reg = READ4(sc, SDMMC_INTMASK);
 	reg &= ~(SDMMC_INTMASK_TXDR | SDMMC_INTMASK_RXDR);
diff --git a/sys/dev/mmc/mmc.c b/sys/dev/mmc/mmc.c
index b8ddb48f84e3..4c46158b8773 100644
--- a/sys/dev/mmc/mmc.c
+++ b/sys/dev/mmc/mmc.c
@@ -1559,17 +1559,14 @@ mmc_host_timing(device_t dev, enum mmc_bus_timing timing)
 static void
 mmc_log_card(device_t dev, struct mmc_ivars *ivar, int newcard)
 {
-	enum mmc_bus_timing max_timing, timing;
+	enum mmc_bus_timing timing;
 
 	device_printf(dev, "Card at relative address 0x%04x%s:\n",
 	    ivar->rca, newcard ? " added" : "");
 	device_printf(dev, " card: %s\n", ivar->card_id_string);
-	max_timing = bus_timing_normal;
 	for (timing = bus_timing_max; timing > bus_timing_normal; timing--) {
-		if (isset(&ivar->timings, timing)) {
-			max_timing = timing;
+		if (isset(&ivar->timings, timing))
 			break;
-		}
 	}
 	device_printf(dev, " quirks: %b\n", ivar->quirks, MMC_QUIRKS_FMT);
 	device_printf(dev, " bus: %ubit, %uMHz (%s timing)\n",
diff --git a/sys/dev/mmc/mmcsd.c b/sys/dev/mmc/mmcsd.c
index 03ec0fc0dc9f..530dd27a43bb 100644
--- a/sys/dev/mmc/mmcsd.c
+++ b/sys/dev/mmc/mmcsd.c
@@ -755,11 +755,9 @@ mmcsd_close(struct disk *dp __unused)
 static void
 mmcsd_strategy(struct bio *bp)
 {
-	struct mmcsd_softc *sc;
 	struct mmcsd_part *part;
 
 	part = bp->bio_disk->d_drv1;
-	sc = part->sc;
 	MMCSD_DISK_LOCK(part);
 	if (part->running > 0 || part->suspend > 0) {
 		bioq_disksort(&part->bio_queue, bp);
diff --git a/sys/dev/ofw/ofw_bus_subr.c b/sys/dev/ofw/ofw_bus_subr.c
index c9e0a5f34510..957520bd9778 100644
--- a/sys/dev/ofw/ofw_bus_subr.c
+++ b/sys/dev/ofw/ofw_bus_subr.c
@@ -386,9 +386,8 @@ ofw_bus_search_intrmap(void *intr, int intrsz, void *regs, int physsz,
 	uint8_t *mptr;
 	pcell_t paddrsz;
 	pcell_t pintrsz;
-	int i, rsz, tsz;
+	int i, tsz;
 
-	rsz = -1;
 	if (imapmsk != NULL) {
 		for (i = 0; i < physsz; i++)
 			ref[i] = uiregs[i] & uiimapmsk[i];
@@ -445,7 +444,7 @@ ofw_bus_msimap(phandle_t node, uint16_t pci_rid, phandle_t *msi_parent,
 {
 	pcell_t *map, mask, msi_base, rid_base, rid_length;
 	ssize_t len;
-	uint32_t masked_rid, rid;
+	uint32_t masked_rid;
 	int err, i;
 
 	/* TODO: This should be OF_searchprop_alloc if we had it */
@@ -462,7 +461,6 @@ ofw_bus_msimap(phandle_t node, uint16_t pci_rid, phandle_t *msi_parent,
 	}
 
 	err = ENOENT;
-	rid = 0;
 	mask = 0xffffffff;
 	OF_getencprop(node, "msi-map-mask", &mask, sizeof(mask));
 
diff --git a/sys/dev/ofw/ofwpci.c b/sys/dev/ofw/ofwpci.c
index 7b52704b79c8..7ebfe4ab86a1 100644
--- a/sys/dev/ofw/ofwpci.c
+++ b/sys/dev/ofw/ofwpci.c
@@ -558,11 +558,8 @@ static int
 ofw_pci_deactivate_resource(device_t bus, device_t child, int type, int rid,
     struct resource *res)
 {
-	struct ofw_pci_softc *sc;
 	vm_size_t psize;
 
-	sc = device_get_softc(bus);
-
 	if (type != SYS_RES_IOPORT && type != SYS_RES_MEMORY) {
 		return (bus_generic_deactivate_resource(bus, child, type, rid,
 		    res));
diff --git a/sys/dev/pci/pci.c b/sys/dev/pci/pci.c
index 42cb89547c78..fb2989aa4d19 100644
--- a/sys/dev/pci/pci.c
+++ b/sys/dev/pci/pci.c
@@ -3980,7 +3980,6 @@ pci_rescan_method(device_t dev)
 {
 #define	REG(n, w)	PCIB_READ_CONFIG(pcib, busno, s, f, n, w)
 	device_t pcib = device_get_parent(dev);
-	struct pci_softc *sc;
 	device_t child, *devlist, *unchanged;
 	int devcount, error, i, j, maxslots, oldcount;
 	int busno, domain, s, f, pcifunchigh;
@@ -4000,7 +3999,6 @@ pci_rescan_method(device_t dev)
 	} else
 		unchanged = NULL;
 
-	sc = device_get_softc(dev);
 	domain = pcib_get_domain(dev);
 	busno = pcib_get_bus(dev);
 	maxslots = PCIB_MAXSLOTS(pcib);
@@ -4077,12 +4075,10 @@ device_t
 pci_add_iov_child(device_t bus, device_t pf, uint16_t rid, uint16_t vid,
     uint16_t did)
 {
-	struct pci_devinfo *pf_dinfo, *vf_dinfo;
+	struct pci_devinfo *vf_dinfo;
 	device_t pcib;
 	int busno, slot, func;
 
-	pf_dinfo = device_get_ivars(pf);
-
 	pcib = device_get_parent(bus);
 
 	PCIB_DECODE_RID(pcib, rid, &busno, &slot, &func);
diff --git a/sys/dev/pci/pci_pci.c b/sys/dev/pci/pci_pci.c
index 939ff4f0abe0..be5b56bc578a 100644
--- a/sys/dev/pci/pci_pci.c
+++ b/sys/dev/pci/pci_pci.c
@@ -1241,10 +1241,8 @@ static void
 pcib_pcie_ab_timeout(void *arg)
 {
 	struct pcib_softc *sc;
-	device_t dev;
 
 	sc = arg;
-	dev = sc->dev;
 	mtx_assert(&Giant, MA_OWNED);
 	if (sc->flags & PCIB_DETACH_PENDING) {
 		sc->flags |= PCIB_DETACHING;
@@ -1484,16 +1482,14 @@ pcib_cfg_save(struct pcib_softc *sc)
 static void
 pcib_cfg_restore(struct pcib_softc *sc)
 {
-	device_t	dev;
 #ifndef NEW_PCIB
 	uint16_t command;
 #endif
-	dev = sc->dev;
 
 #ifdef NEW_PCIB
 	pcib_write_windows(sc, WIN_IO | WIN_MEM | WIN_PMEM);
 #else
-	command = pci_read_config(dev, PCIR_COMMAND, 2);
+	command = pci_read_config(sc->dev, PCIR_COMMAND, 2);
 	if (command & PCIM_CMD_PORTEN)
 		pcib_set_io_decode(sc);
 	if (command & PCIM_CMD_MEMEN)
diff --git a/sys/dev/smc/if_smc_fdt.c b/sys/dev/smc/if_smc_fdt.c
index d010f93723ce..baca0bd6113e 100644
--- a/sys/dev/smc/if_smc_fdt.c
+++ b/sys/dev/smc/if_smc_fdt.c
@@ -84,17 +84,8 @@ smc_fdt_probe(device_t dev)
 static int
 smc_fdt_attach(device_t dev)
 {
-	int	err;
- 	struct	smc_softc *sc;
 
-	sc = device_get_softc(dev);
-
-	err = smc_attach(dev);
-	if (err) {
-		return (err);
-	}
-
-	return (0);
+	return smc_attach(dev);
 }
 
 static int
diff --git a/sys/dev/uart/uart_bus_acpi.c b/sys/dev/uart/uart_bus_acpi.c
index b1bb55a3410d..88b1480064f4 100644
--- a/sys/dev/uart/uart_bus_acpi.c
+++ b/sys/dev/uart/uart_bus_acpi.c
@@ -104,13 +104,11 @@ static int
 uart_acpi_probe(device_t dev)
 {
 	struct uart_softc *sc;
-	device_t parent;
 
-	parent = device_get_parent(dev);
 	sc = device_get_softc(dev);
 
 #if defined(__i386__) || defined(__amd64__)
-	if (!ISA_PNP_PROBE(parent, dev, acpi_ns8250_ids)) {
+	if (!ISA_PNP_PROBE(device_get_parent(dev), dev, acpi_ns8250_ids)) {
 		sc->sc_class = &uart_ns8250_class;
 		return (uart_bus_probe(dev, 0, 0, 0, 0, 0));
 	}
diff --git a/sys/dev/uart/uart_dev_pl011.c b/sys/dev/uart/uart_dev_pl011.c
index 7568327d875c..3f232d5f6e8a 100644
--- a/sys/dev/uart/uart_dev_pl011.c
+++ b/sys/dev/uart/uart_dev_pl011.c
@@ -381,10 +381,8 @@ uart_pl011_bus_getsig(struct uart_softc *sc)
 static int
 uart_pl011_bus_ioctl(struct uart_softc *sc, int request, intptr_t data)
 {
-	struct uart_bas *bas;
 	int error;
 
-	bas = &sc->sc_bas;
 	error = 0;
 	uart_lock(sc->sc_hwmtx);
 	switch (request) {
diff --git a/sys/dev/uart/uart_dev_snps.c b/sys/dev/uart/uart_dev_snps.c
index e83e75182844..a29b805ea9cf 100644
--- a/sys/dev/uart/uart_dev_snps.c
+++ b/sys/dev/uart/uart_dev_snps.c
@@ -110,9 +110,7 @@ UART_FDT_CLASS(compat_data);
 static int
 snps_get_clocks(device_t dev, clk_t *baudclk, clk_t *apb_pclk)
 {
-	struct snps_softc *sc;
 
-	sc = device_get_softc(dev);
 	*baudclk = NULL;
 	*apb_pclk = NULL;
 
diff --git a/sys/dev/usb/controller/dwc_otg_fdt.c b/sys/dev/usb/controller/dwc_otg_fdt.c
index b33184c97214..c333aa98add7 100644
--- a/sys/dev/usb/controller/dwc_otg_fdt.c
+++ b/sys/dev/usb/controller/dwc_otg_fdt.c
@@ -170,7 +170,6 @@ int
 dwc_otg_detach(device_t dev)
 {
 	struct dwc_otg_fdt_softc *sc = device_get_softc(dev);
-	int err;
 
 	/* during module unload there are lots of children leftover */
 	device_delete_children(dev);
@@ -181,7 +180,7 @@ dwc_otg_detach(device_t dev)
 		 */
 		dwc_otg_uninit(&sc->sc_otg);
 
-		err = bus_teardown_intr(dev, sc->sc_otg.sc_irq_res,
+		bus_teardown_intr(dev, sc->sc_otg.sc_irq_res,
 		    sc->sc_otg.sc_intr_hdl);
 		sc->sc_otg.sc_intr_hdl = NULL;
 	}
diff --git a/sys/dev/usb/controller/ehci.c b/sys/dev/usb/controller/ehci.c
index 4229d96ab204..aa1f9b31b4d2 100644
--- a/sys/dev/usb/controller/ehci.c
+++ b/sys/dev/usb/controller/ehci.c
@@ -1194,9 +1194,7 @@ ehci_non_isoc_done_sub(struct usb_xfer *xfer)
 static void
 ehci_non_isoc_done(struct usb_xfer *xfer)
 {
-	ehci_softc_t *sc = EHCI_BUS2SC(xfer->xroot->bus);
 	ehci_qh_t *qh;
-	uint32_t status;
 	usb_error_t err = 0;
 
 	DPRINTFN(13, "xfer=%p endpoint=%p transfer done\n",
@@ -1216,8 +1214,6 @@ ehci_non_isoc_done(struct usb_xfer *xfer)
 
 	usb_pc_cpu_invalidate(qh->page_cache);
 
-	status = hc32toh(sc, qh->qh_qtd.qtd_status);
-
 	/* reset scanner */
 
 	xfer->td_transfer_cache = xfer->td_transfer_first;
diff --git a/sys/dev/usb/controller/ohci.c b/sys/dev/usb/controller/ohci.c
index ae9ae4488b89..dffa3676cb7d 100644
--- a/sys/dev/usb/controller/ohci.c
+++ b/sys/dev/usb/controller/ohci.c
@@ -2385,7 +2385,6 @@ ohci_xfer_setup(struct usb_setup_params *parm)
 {
 	struct usb_page_search page_info;
 	struct usb_page_cache *pc;
-	ohci_softc_t *sc;
 	struct usb_xfer *xfer;
 	void *last_obj;
 	uint32_t ntd;
@@ -2393,7 +2392,6 @@ ohci_xfer_setup(struct usb_setup_params *parm)
 	uint32_t nqh;
 	uint32_t n;
 
-	sc = OHCI_BUS2SC(parm->udev->bus);
 	xfer = parm->curr_xfer;
 
 	parm->hc_max_packet_size = 0x500;
diff --git a/sys/dev/usb/controller/xhci.c b/sys/dev/usb/controller/xhci.c
index 12ecdefffd81..ac4916700e12 100644
--- a/sys/dev/usb/controller/xhci.c
+++ b/sys/dev/usb/controller/xhci.c
@@ -3714,13 +3714,11 @@ xhci_xfer_setup(struct usb_setup_params *parm)
 {
 	struct usb_page_search page_info;
 	struct usb_page_cache *pc;
-	struct xhci_softc *sc;
 	struct usb_xfer *xfer;
 	void *last_obj;
 	uint32_t ntd;
 	uint32_t n;
 
-	sc = XHCI_BUS2SC(parm->udev->bus);
 	xfer = parm->curr_xfer;
 
 	/*
diff --git a/sys/dev/usb/storage/umass.c b/sys/dev/usb/storage/umass.c
index 3dd3bfa4b3df..cfd2ba174b41 100644
--- a/sys/dev/usb/storage/umass.c
+++ b/sys/dev/usb/storage/umass.c
@@ -1089,7 +1089,6 @@ static void
 umass_init_shuttle(struct umass_softc *sc)
 {
 	struct usb_device_request req;
-	usb_error_t err;
 	uint8_t status[2] = {0, 0};
 
 	/*
@@ -1102,7 +1101,7 @@ umass_init_shuttle(struct umass_softc *sc)
 	req.wIndex[0] = sc->sc_iface_no;
 	req.wIndex[1] = 0;
 	USETW(req.wLength, sizeof(status));
-	err = usbd_do_request(sc->sc_udev, NULL, &req, &status);
+	usbd_do_request(sc->sc_udev, NULL, &req, &status);
 
 	DPRINTF(sc, UDMASS_GEN, "Shuttle init returned 0x%02x%02x\n",
 	    status[0], status[1]);
diff --git a/sys/dev/usb/usb_dev.c b/sys/dev/usb/usb_dev.c
index 206d0ec3c716..72c75dcd2468 100644
--- a/sys/dev/usb/usb_dev.c
+++ b/sys/dev/usb/usb_dev.c
@@ -878,7 +878,7 @@ usb_open(struct cdev *dev, int fflags, int devtype, struct thread *td)
 	struct usb_fs_privdata* pd = (struct usb_fs_privdata*)dev->si_drv1;
 	struct usb_cdev_refdata refs;
 	struct usb_cdev_privdata *cpd;
-	int err, ep;
+	int err;
 
 	DPRINTFN(2, "%s fflags=0x%08x\n", devtoname(dev), fflags);
 
@@ -890,7 +890,6 @@ usb_open(struct cdev *dev, int fflags, int devtype, struct thread *td)
 	}
 
 	cpd = malloc(sizeof(*cpd), M_USBDEV, M_WAITOK | M_ZERO);
-	ep = cpd->ep_addr = pd->ep_addr;
 
 	usb_loc_fill(pd, cpd);
 	err = usb_ref_device(cpd, &refs, 1);
@@ -1412,8 +1411,6 @@ usb_read(struct cdev *dev, struct uio *uio, int ioflag)
 	struct usb_cdev_privdata* cpd;
 	struct usb_fifo *f;
 	struct usb_mbuf *m;
-	int fflags;
-	int resid;
 	int io_len;
 	int err;
 	uint8_t tr_data = 0;
@@ -1426,8 +1423,6 @@ usb_read(struct cdev *dev, struct uio *uio, int ioflag)
 	if (err)
 		return (ENXIO);
 
-	fflags = cpd->fflags;
-
 	f = refs.rxfifo;
 	if (f == NULL) {
 		/* should not happen */
@@ -1435,8 +1430,6 @@ usb_read(struct cdev *dev, struct uio *uio, int ioflag)
 		return (EPERM);
 	}
 
-	resid = uio->uio_resid;
-
 	mtx_lock(f->priv_mtx);
 
 	/* check for permanent read error */
@@ -1536,8 +1529,6 @@ usb_write(struct cdev *dev, struct uio *uio, int ioflag)
 	struct usb_fifo *f;
 	struct usb_mbuf *m;
 	uint8_t *pdata;
-	int fflags;
-	int resid;
 	int io_len;
 	int err;
 	uint8_t tr_data = 0;
@@ -1552,15 +1543,12 @@ usb_write(struct cdev *dev, struct uio *uio, int ioflag)
 	if (err)
 		return (ENXIO);
 
-	fflags = cpd->fflags;
-
 	f = refs.txfifo;
 	if (f == NULL) {
 		/* should not happen */
 		usb_unref_device(cpd, &refs);
 		return (EPERM);
 	}
-	resid = uio->uio_resid;
 
 	mtx_lock(f->priv_mtx);
 
diff --git a/sys/dev/vnic/nic_main.c b/sys/dev/vnic/nic_main.c
index 9391e6a702b9..8e6aa60f6ca8 100644
--- a/sys/dev/vnic/nic_main.c
+++ b/sys/dev/vnic/nic_main.c
@@ -761,9 +761,6 @@ static void
 nic_send_rss_size(struct nicpf *nic, int vf)
 {
 	union nic_mbx mbx = {};
-	uint64_t  *msg;
-
-	msg = (uint64_t *)&mbx;
 
 	mbx.rss_size.msg = NIC_MBOX_MSG_RSS_SIZE;
 	mbx.rss_size.ind_tbl_size = nic->rss_ind_tbl_size;
diff --git a/sys/dev/vnic/nicvf_main.c b/sys/dev/vnic/nicvf_main.c
index 5e6cf9e6884a..19ea5bcdb7e5 100644
--- a/sys/dev/vnic/nicvf_main.c
+++ b/sys/dev/vnic/nicvf_main.c
@@ -425,7 +425,6 @@ nicvf_if_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 	struct nicvf *nic;
 	struct rcv_queue *rq;
 	struct ifreq *ifr;
-	uint32_t flags;
 	int mask, err;
 	int rq_idx;
 #if defined(INET) || defined(INET6)
@@ -482,7 +481,6 @@ nicvf_if_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 		NICVF_CORE_LOCK(nic);
 		if (if_getflags(ifp) & IFF_UP) {
 			if (if_getdrvflags(ifp) & IFF_DRV_RUNNING) {
-				flags = if_getflags(ifp) ^ nic->if_flags;
 				if ((nic->if_flags & if_getflags(ifp)) &
 				    IFF_PROMISC) {
 					/* Change promiscous mode */
diff --git a/sys/dev/vnic/nicvf_queues.c b/sys/dev/vnic/nicvf_queues.c
index 7a1dda8f3570..d469067c1cf8 100644
--- a/sys/dev/vnic/nicvf_queues.c
+++ b/sys/dev/vnic/nicvf_queues.c
@@ -1714,13 +1714,12 @@ nicvf_sq_disable(struct nicvf *nic, int qidx)
 static void
 nicvf_sq_free_used_descs(struct nicvf *nic, struct snd_queue *sq, int qidx)
 {
-	uint64_t head, tail;
+	uint64_t head;
 	struct snd_buff *snd_buff;
 	struct sq_hdr_subdesc *hdr;
 
 	NICVF_TX_LOCK(sq);
 	head = nicvf_queue_reg_read(nic, NIC_QSET_SQ_0_7_HEAD, qidx) >> 4;
-	tail = nicvf_queue_reg_read(nic, NIC_QSET_SQ_0_7_TAIL, qidx) >> 4;
 	while (sq->head != head) {
 		hdr = (struct sq_hdr_subdesc *)GET_SQ_DESC(sq, sq->head);
 		if (hdr->subdesc_type != SQ_DESC_TYPE_HEADER) {