From nobody Sat Nov 30 10:44:39 2024 Received: from out-184.mta1.migadu.com (out-184.mta1.migadu.com [95.215.58.184]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 96B8518CBF0 for ; Mon, 9 Sep 2024 23:09:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.184 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725923361; cv=none; b=i/sdFN9Srzog18OoJDkabiP2fX/FlLSroZ4IKNkB0R1SM0DhGkAAeobEtIGMtcs6K7PwyJJGRUhzPGUKFUodiB04Z1g1jJyBiXg/tq1o5xxWVokcTF2RTs6w2NeW+PgQl+4ZwcYUV+MX1FSyXdeuDn27GGLanAesV69+RlkFtYQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725923361; c=relaxed/simple; bh=XBlmBZ8LFNCjnsRbnix/NcPqlypUOFlvAhyzhCweOFg=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=gsDqfgfZFBjEFlHnnu2DkI1er52RrcmFhwt0Cnt8SVT6t9WAg9BXuQjyojOG8j7AhwSzJykfoqiUQ5qlIG0YywWTUeeRTu8tyncDmRXz+j6yhCtxvCdObusszI/kRYJww1Vh89op3cWyNdFvlPr6xJv7FzyL6mHzcNmcPxLuos8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=fokhnc60; arc=none smtp.client-ip=95.215.58.184 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="fokhnc60" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1725923355; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=oYqzLmU8Wwh+yV2OBnKEU0j9ng/GD4hfiT1RPK+msTg=; b=fokhnc608jJF/K2dN/Aq8rKKEJ2UXmEzP/3e38gbFBr/MY6gB2YUsF7heYJMyGirCtau99 TYrQFQ/6YG4PPccrwhSQJ4CrvjxLGow9O3ieQNuuBsunpKWOH+/UvJ0C8/kMbQLU9Hy5lR Dn7XxZVg/T74ba+8ng8uRF3zbBcF7Uc= From: Sean Anderson To: Radhey Shyam Pandey , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , netdev@vger.kernel.org Cc: Andy Chiu , linux-kernel@vger.kernel.org, Simon Horman , Ariane Keller , Daniel Borkmann , linux-arm-kernel@lists.infradead.org, Michal Simek , Sean Anderson Subject: [PATCH net v2] net: xilinx: axienet: Fix IRQ coalescing packet count overflow Date: Mon, 9 Sep 2024 19:09:08 -0400 Message-Id: <20240909230908.1319982-1-sean.anderson@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" If coalece_count is greater than 255 it will not fit in the register and will overflow. This can be reproduced by running # ethtool -C ethX rx-frames 256 which will result in a timeout of 0us instead. Fix this by clamping the counts to the maximum value. Signed-off-by: Sean Anderson Fixes: 8a3b7a252dca ("drivers/net/ethernet/xilinx: added Xilinx AXI Etherne= t driver") Reviewed-by: Shannon Nelson --- Changes in v2: - Use FIELD_MAX to extract the max value from the mask - Expand the commit message with an example on how to reproduce this issue drivers/net/ethernet/xilinx/xilinx_axienet.h | 5 ++--- drivers/net/ethernet/xilinx/xilinx_axienet_main.c | 8 ++++++-- 2 files changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet.h b/drivers/net/eth= ernet/xilinx/xilinx_axienet.h index 1223fcc1a8da..54db69893565 100644 --- a/drivers/net/ethernet/xilinx/xilinx_axienet.h +++ b/drivers/net/ethernet/xilinx/xilinx_axienet.h @@ -109,11 +109,10 @@ #define XAXIDMA_BD_CTRL_TXEOF_MASK 0x04000000 /* Last tx packet */ #define XAXIDMA_BD_CTRL_ALL_MASK 0x0C000000 /* All control bits */ =20 -#define XAXIDMA_DELAY_MASK 0xFF000000 /* Delay timeout counter */ -#define XAXIDMA_COALESCE_MASK 0x00FF0000 /* Coalesce counter */ +#define XAXIDMA_DELAY_MASK ((u32)0xFF000000) /* Delay timeout counter */ +#define XAXIDMA_COALESCE_MASK ((u32)0x00FF0000) /* Coalesce counter */ =20 #define XAXIDMA_DELAY_SHIFT 24 -#define XAXIDMA_COALESCE_SHIFT 16 =20 #define XAXIDMA_IRQ_IOC_MASK 0x00001000 /* Completion intr */ #define XAXIDMA_IRQ_DELAY_MASK 0x00002000 /* Delay interrupt */ diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/ne= t/ethernet/xilinx/xilinx_axienet_main.c index 9eb300fc3590..89b63695293d 100644 --- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c +++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c @@ -252,7 +252,9 @@ static u32 axienet_usec_to_timer(struct axienet_local *= lp, u32 coalesce_usec) static void axienet_dma_start(struct axienet_local *lp) { /* Start updating the Rx channel control register */ - lp->rx_dma_cr =3D (lp->coalesce_count_rx << XAXIDMA_COALESCE_SHIFT) | + lp->rx_dma_cr =3D FIELD_PREP(XAXIDMA_COALESCE_MASK, + min(lp->coalesce_count_rx, + FIELD_MAX(XAXIDMA_COALESCE_MASK))) | XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_ERROR_MASK; /* Only set interrupt delay timer if not generating an interrupt on * the first RX packet. Otherwise leave at 0 to disable delay interrupt. @@ -264,7 +266,9 @@ static void axienet_dma_start(struct axienet_local *lp) axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, lp->rx_dma_cr); =20 /* Start updating the Tx channel control register */ - lp->tx_dma_cr =3D (lp->coalesce_count_tx << XAXIDMA_COALESCE_SHIFT) | + lp->tx_dma_cr =3D FIELD_PREP(XAXIDMA_COALESCE_MASK, + min(lp->coalesce_count_tx, + FIELD_MAX(XAXIDMA_COALESCE_MASK))) | XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_ERROR_MASK; /* Only set interrupt delay timer if not generating an interrupt on * the first TX packet. Otherwise leave at 0 to disable delay interrupt. --=20 2.35.1.1320.gc452695387.dirty