From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dmitry Fleytman , Leonid Bloch , Aaron Brown , Jeff Kirsher , Sasha Levin Subject: [PATCH 4.4 016/192] [PATCH 016/135] e1000e: fix division by zero on jumbo MTUs Date: Mon, 12 Sep 2016 18:58:45 +0200 Message-Id: <20160912152159.590258099@linuxfoundation.org> In-Reply-To: <20160912152158.855601725@linuxfoundation.org> References: <20160912152158.855601725@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit b77ac46bbae862dcb3f51296825c940404c69b0f ] This patch fixes possible division by zero in receive interrupt handler when working without adaptive interrupt moderation. The adaptive interrupt moderation mechanism is typically disabled on jumbo MTUs. Signed-off-by: Dmitry Fleytman Signed-off-by: Leonid Bloch Tested-by: Aaron Brown Signed-off-by: Jeff Kirsher Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/intel/e1000e/netdev.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/net/ethernet/intel/e1000e/netdev.c +++ b/drivers/net/ethernet/intel/e1000e/netdev.c @@ -1959,8 +1959,10 @@ static irqreturn_t e1000_intr_msix_rx(in * previous interrupt. */ if (rx_ring->set_itr) { - writel(1000000000 / (rx_ring->itr_val * 256), - rx_ring->itr_register); + u32 itr = rx_ring->itr_val ? + 1000000000 / (rx_ring->itr_val * 256) : 0; + + writel(itr, rx_ring->itr_register); rx_ring->set_itr = 0; }