From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DA1B7C43381 for ; Tue, 12 Mar 2019 18:10:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A16692063F for ; Tue, 12 Mar 2019 18:10:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552414214; bh=5RXW2Qw0BwncpqS2jxGguYG+FtgIe4cVEHwl991RYRI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=plXL2sQrzbtF2gt5jH15JTPzwIRr1nN7IuEFtqkbN5pTYJHIZlvu6ivW+0kjx2XMY QcFU3kQhPuvma9Jrp1SoS5lwONVoDAfs6MJlefVHeZ7huQYF8UUQWmPYpOFEERWauO maVFJMtH/nsJUlb19At8veBrjlldebmF3g/Y24pI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729181AbfCLSKN (ORCPT ); Tue, 12 Mar 2019 14:10:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:46170 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727100AbfCLRL5 (ORCPT ); Tue, 12 Mar 2019 13:11:57 -0400 Received: from localhost (unknown [104.133.8.98]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 364AD2173C; Tue, 12 Mar 2019 17:11:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552410716; bh=5RXW2Qw0BwncpqS2jxGguYG+FtgIe4cVEHwl991RYRI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HI+tVdqYicYn7sJpIHG/+7R4jY4p1IkyoeYHBlQNlu48EFU5RRQEfU/9Aun3JZMzZ PfQAWyS8RKXQ1WPuP/WvVDgYSZCc7ai8j/LW2HC6b1OdIOecDuR56aEP8a0o8TEwEC fXiwUxWttfelplvpxa3z5WJ8eqzo4RWRtDTGO8Pk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tomonori Sakita , Atsushi Nemoto , Dalon L Westergreen , Thor Thayer , "David S. Miller" , Sasha Levin Subject: [PATCH 4.20 031/171] net: altera_tse: fix msgdma_tx_completion on non-zero fill_level case Date: Tue, 12 Mar 2019 10:06:51 -0700 Message-Id: <20190312170350.686226387@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190312170347.868927101@linuxfoundation.org> References: <20190312170347.868927101@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit 6571ebce112a21ec9be68ef2f53b96fcd41fd81b ] If fill_level was not zero and status was not BUSY, result of "tx_prod - tx_cons - inuse" might be zero. Subtracting 1 unconditionally results invalid negative return value on this case. Make sure not to return an negative value. Signed-off-by: Tomonori Sakita Signed-off-by: Atsushi Nemoto Reviewed-by: Dalon L Westergreen Acked-by: Thor Thayer Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/ethernet/altera/altera_msgdma.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/altera/altera_msgdma.c b/drivers/net/ethernet/altera/altera_msgdma.c index 0fb986ba3290..0ae723f75341 100644 --- a/drivers/net/ethernet/altera/altera_msgdma.c +++ b/drivers/net/ethernet/altera/altera_msgdma.c @@ -145,7 +145,8 @@ u32 msgdma_tx_completions(struct altera_tse_private *priv) & 0xffff; if (inuse) { /* Tx FIFO is not empty */ - ready = priv->tx_prod - priv->tx_cons - inuse - 1; + ready = max_t(int, + priv->tx_prod - priv->tx_cons - inuse - 1, 0); } else { /* Check for buffered last packet */ status = csrrd32(priv->tx_dma_csr, msgdma_csroffs(status)); -- 2.19.1