From: Yuji Ishikawa <yuji2.ishikawa@xxxxxxxxxxxxx> commit 928d6fe996f69330ded6b887baf4534c5fac7988 upstream. Variable clk_sel_val is not initialized in the default case of the first switch statement. In that case, the function should return immediately without any changes to the hardware. Reported-by: kernel test robot <lkp@xxxxxxxxx> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Fixes: b38dd98ff8d0 ("net: stmmac: Add Toshiba Visconti SoCs glue driver") Signed-off-by: Yuji Ishikawa <yuji2.ishikawa@xxxxxxxxxxxxx> Reviewed-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@xxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/stmicro/stmmac/dwmac-visconti.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-visconti.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-visconti.c @@ -49,13 +49,15 @@ struct visconti_eth { void __iomem *reg; u32 phy_intf_sel; struct clk *phy_ref_clk; + struct device *dev; spinlock_t lock; /* lock to protect register update */ }; static void visconti_eth_fix_mac_speed(void *priv, unsigned int speed) { struct visconti_eth *dwmac = priv; - unsigned int val, clk_sel_val; + struct net_device *netdev = dev_get_drvdata(dwmac->dev); + unsigned int val, clk_sel_val = 0; unsigned long flags; spin_lock_irqsave(&dwmac->lock, flags); @@ -85,7 +87,9 @@ static void visconti_eth_fix_mac_speed(v break; default: /* No bit control */ - break; + netdev_err(netdev, "Unsupported speed request (%d)", speed); + spin_unlock_irqrestore(&dwmac->lock, flags); + return; } writel(val, dwmac->reg + MAC_CTRL_REG); @@ -230,6 +234,7 @@ static int visconti_eth_dwmac_probe(stru spin_lock_init(&dwmac->lock); dwmac->reg = stmmac_res.addr; + dwmac->dev = &pdev->dev; plat_dat->bsp_priv = dwmac; plat_dat->fix_mac_speed = visconti_eth_fix_mac_speed; Patches currently in stable-queue which might be from yuji2.ishikawa@xxxxxxxxxxxxx are queue-5.15/net-stmmac-dwmac-visconti-no-change-to-ether_clock_sel-for-unexpected-speed-request.patch