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=-9.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 8B8E8C43381 for ; Sat, 23 Feb 2019 21:10:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4F46F2085A for ; Sat, 23 Feb 2019 21:10:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550956222; bh=0SeNmAA7hH0M4ARlqj/TFjRbHU1OUisX6F8lskq7uBQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=K5RB7mTjNu6Jfky12+6qnzlspuKORO3nm/O5g9wZhP2mEyiVqZixQTH4hI9ozAUz/ BMk1VhX7ZOJr5xxQ4KV0M6Z1bcuK/bv0+ISOTE7iVPEt//1ldnLoqo7wO+Fy3sLqgB V1KALoyYVrOcUqSy8d671TLmBCiMfcFjZsSINhzY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729130AbfBWVKV (ORCPT ); Sat, 23 Feb 2019 16:10:21 -0500 Received: from mail.kernel.org ([198.145.29.99]:46280 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728940AbfBWVKR (ORCPT ); Sat, 23 Feb 2019 16:10:17 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D896C2085A; Sat, 23 Feb 2019 21:10:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550956216; bh=0SeNmAA7hH0M4ARlqj/TFjRbHU1OUisX6F8lskq7uBQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CUlhQTGDnq4V7mn4FMhbYE5KRvKYY7g8uS9F8ML5D5aeYLkQly+aWzU1lODkk/9x1 Pff5G4Io4Tubi4xm6DGgfj3ddPSMVWBCFT01R/xyu9NqYmo5hi/O/yHPlHueGwTfHl fLz99oU6BeQ60D1h4Qw0f0lUKotiOfi/g/AmDvWQ= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Tomonori Sakita , Atsushi Nemoto , "David S . Miller" , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 15/32] net: altera_tse: fix msgdma_tx_completion on non-zero fill_level case Date: Sat, 23 Feb 2019 16:09:34 -0500 Message-Id: <20190223210951.202268-15-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190223210951.202268-1-sashal@kernel.org> References: <20190223210951.202268-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Tomonori Sakita [ 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 0fb986ba32905..0ae723f753417 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