From nobody Tue Feb 10 23:55:34 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=gmail.com ARC-Seal: i=1; a=rsa-sha256; t=1613081088; cv=none; d=zohomail.com; s=zohoarc; b=Y2nKUHAgRsgRaQkZHxTaV7yP6M9KJzH8VpOgdkeqpNjwCe66BzAVat0KypRT1j8cW3DlncTD9MKaE6XgDzlnAvtTwPsMkMQQ8XYmUFMFz5ihHxe0L/mt9RQQ+Z7pWFuPDyOqVpWTK/3NjhjfICZWIIdpRhYnPBFYZeCJZMqB26Q= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1613081088; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=kREa/WLvCSnwORBa58MC0Qb48ehGXAj/cQQKJfewFlE=; b=YBHxpoNOKbB2cTgasJpsqG984EZ4Nfr+q5S528k41laJz+GXjM9igb+1AoiL7tdM8RwW4PjMou914lOcavbKYF3EvXg8cnEt2/POLaRpevL0EvqWMf15DlQOIr72numEEPPGERd2SSRMuxjEBgp3N1KrRuF8JkbSuQWO14BLWd8= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1613081088247333.11483428054987; Thu, 11 Feb 2021 14:04:48 -0800 (PST) Received: from localhost ([::1]:49312 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lAK4s-00021H-Lt for importer@patchew.org; Thu, 11 Feb 2021 17:04:46 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:59314) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lAK2D-0000Es-2B; Thu, 11 Feb 2021 17:02:01 -0500 Received: from mail-ed1-x535.google.com ([2a00:1450:4864:20::535]:45933) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1lAK2A-0005oy-Dy; Thu, 11 Feb 2021 17:02:00 -0500 Received: by mail-ed1-x535.google.com with SMTP id t5so8537065eds.12; Thu, 11 Feb 2021 14:01:57 -0800 (PST) Received: from tuf.home (2a02-a456-6be8-1-df14-48c0-797d-7ff1.fixed6.kpn.net. [2a02:a456:6be8:1:df14:48c0:797d:7ff1]) by smtp.gmail.com with ESMTPSA id n16sm5496588ejy.23.2021.02.11.14.01.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 11 Feb 2021 14:01:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=kREa/WLvCSnwORBa58MC0Qb48ehGXAj/cQQKJfewFlE=; b=X7WsLVb7O/CO7df9YHZaoF8qUSwrfLo+ZqKuFKRrkIY/1T3LhHnObZo7S9yDHGrngO 74vzAFsJAETY7xhEhYNb1/nmtqhDJHvDwUbQpJ1OX9yg2q+sddlw0e0B7U7Ot0CNQ8yU 75Jd3GqHZAcfzYt1aMvCzV4VntMSRixmvVzsB6EagcsJlJT0W/eO/hYjpibKOlF5bveQ GVSWhlChADCqtDgXSvjUyg6Wxmv0iEbE/kNy6noZFGvpGmhdQWCxokxIMzTnirgYz9AA 0zKg5HD0X6O80msHYwnq7/s1ro1T3M+CRMZIzVfV+nPXtf+WaIzdkK7ZWDrs/FINKTXj SjqQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=kREa/WLvCSnwORBa58MC0Qb48ehGXAj/cQQKJfewFlE=; b=l0QStO8h8GzViKs5umkrJOuCEE7Xtcoor11/n3ygtAosRd8bHvArWemx4ZFCjT0MnF AWF2XfTGwTYfbMm1NZid7x5w6ZDeUUWLda/JDfqD2WoStj0AXMOpmvYF/5pJ0OTqgzbW myJDKNT9Xo7tfBzYMV1/Y65dVLNZkbeYDyEkrPjS7/0cWi0Kyd7/Iepegue7/DzkXuPK ZHKeiQHhW/OBxmXRt6QXvTqiSl84ZKXnvoEniDS2TulfcZS+b9oUxf/VM21BrK7VVwbt 6FB724lgh98hglgnCLValyyoQ8sSU35YYixo9zCZuV32Gx2DK/fKjoYkKeN/HRwR+Mdp X7lg== X-Gm-Message-State: AOAM530KwWlqq54t4o6FpIly5icfoLx8i3HNH5saff2lD7OVyfpOFwnh 4ynnWc4C+WPX/J+nEAfHzN/jwFJRMVU= X-Google-Smtp-Source: ABdhPJxJGoAA9iyo8El/L65A8L2Rby2UFIkkXCFu0r4y0wCPpRwyyLF6LxJr5vBwQrzK9YW2TQeeDQ== X-Received: by 2002:a05:6402:31a3:: with SMTP id dj3mr229412edb.172.1613080916639; Thu, 11 Feb 2021 14:01:56 -0800 (PST) From: Niek Linnenbank To: qemu-devel@nongnu.org Subject: [PATCH 2/2] hw/net/allwinner-sun8i-emac: traverse transmit queue using TX_CUR_DESC register value Date: Thu, 11 Feb 2021 23:00:55 +0100 Message-Id: <20210211220055.19047-3-nieklinnenbank@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210211220055.19047-1-nieklinnenbank@gmail.com> References: <20210211220055.19047-1-nieklinnenbank@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=2a00:1450:4864:20::535; envelope-from=nieklinnenbank@gmail.com; helo=mail-ed1-x535.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: peter.maydell@linaro.org, f4bug@amsat.org, b.galvani@gmail.com, Niek Linnenbank , qemu-arm@nongnu.org, Pavel.Dovgaluk@ispras.ru, crosa@redhat.com, philmd@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Type: text/plain; charset="utf-8" Currently the emulated EMAC for sun8i always traverses the transmit queue from the head when transferring packets. It searches for a list of consecut= ive descriptors whichs are flagged as ready for processing and transmits their = payloads accordingly. The controller stops processing once it finds a descriptor tha= t is not marked ready. While the above behaviour works in most situations, it is not the same as t= he actual EMAC in hardware. Actual hardware uses the TX_CUR_DESC register value to ke= ep track of the last position in the transmit queue and continues processing from th= at position when software triggers the start of DMA processing. The currently emulated = behaviour can lead to packet loss on transmit when software fills the transmit queue with= ready descriptors that overlap the tail of the circular list. This commit modifies the emulated EMAC for sun8i such that it processes the transmit queue using the TX_CUR_DESC register in the same way as hardwa= re. Signed-off-by: Niek Linnenbank Reviewed-by: Philippe Mathieu-Daud=C3=A9 --- hw/net/allwinner-sun8i-emac.c | 58 +++++++++++++++++++---------------- 1 file changed, 32 insertions(+), 26 deletions(-) diff --git a/hw/net/allwinner-sun8i-emac.c b/hw/net/allwinner-sun8i-emac.c index 042768922c..e586c147e5 100644 --- a/hw/net/allwinner-sun8i-emac.c +++ b/hw/net/allwinner-sun8i-emac.c @@ -339,35 +339,40 @@ static void allwinner_sun8i_emac_update_irq(AwSun8iEm= acState *s) qemu_set_irq(s->irq, (s->int_sta & s->int_en) !=3D 0); } =20 -static uint32_t allwinner_sun8i_emac_next_desc(AwSun8iEmacState *s, - FrameDescriptor *desc, - size_t min_size) +static bool allwinner_sun8i_emac_desc_owned(FrameDescriptor *desc, + size_t min_buf_size) { - uint32_t paddr =3D desc->next; + return (desc->status & DESC_STATUS_CTL) && (min_buf_size =3D=3D 0 || + (desc->status2 & DESC_STATUS2_BUF_SIZE_MASK) >=3D min_buf_size); +} =20 - dma_memory_read(&s->dma_as, paddr, desc, sizeof(*desc)); +static void allwinner_sun8i_emac_get_desc(AwSun8iEmacState *s, + FrameDescriptor *desc, + uint32_t phys_addr) +{ + dma_memory_read(&s->dma_as, phys_addr, desc, sizeof(*desc)); +} =20 - if ((desc->status & DESC_STATUS_CTL) && - (desc->status2 & DESC_STATUS2_BUF_SIZE_MASK) >=3D min_size) { - return paddr; - } else { - return 0; - } +static uint32_t allwinner_sun8i_emac_next_desc(AwSun8iEmacState *s, + FrameDescriptor *desc) +{ + const uint32_t nxt =3D desc->next; + allwinner_sun8i_emac_get_desc(s, desc, nxt); + return nxt; } =20 -static uint32_t allwinner_sun8i_emac_get_desc(AwSun8iEmacState *s, - FrameDescriptor *desc, - uint32_t start_addr, - size_t min_size) +static uint32_t allwinner_sun8i_emac_find_desc(AwSun8iEmacState *s, + FrameDescriptor *desc, + uint32_t start_addr, + size_t min_size) { uint32_t desc_addr =3D start_addr; =20 /* Note that the list is a cycle. Last entry points back to the head. = */ while (desc_addr !=3D 0) { - dma_memory_read(&s->dma_as, desc_addr, desc, sizeof(*desc)); + allwinner_sun8i_emac_get_desc(s, desc, desc_addr); =20 - if ((desc->status & DESC_STATUS_CTL) && - (desc->status2 & DESC_STATUS2_BUF_SIZE_MASK) >=3D min_size) { + if (allwinner_sun8i_emac_desc_owned(desc, min_size)) { return desc_addr; } else if (desc->next =3D=3D start_addr) { break; @@ -383,14 +388,14 @@ static uint32_t allwinner_sun8i_emac_rx_desc(AwSun8iE= macState *s, FrameDescriptor *desc, size_t min_size) { - return allwinner_sun8i_emac_get_desc(s, desc, s->rx_desc_curr, min_siz= e); + return allwinner_sun8i_emac_find_desc(s, desc, s->rx_desc_curr, min_si= ze); } =20 static uint32_t allwinner_sun8i_emac_tx_desc(AwSun8iEmacState *s, - FrameDescriptor *desc, - size_t min_size) + FrameDescriptor *desc) { - return allwinner_sun8i_emac_get_desc(s, desc, s->tx_desc_head, min_siz= e); + allwinner_sun8i_emac_get_desc(s, desc, s->tx_desc_curr); + return s->tx_desc_curr; } =20 static void allwinner_sun8i_emac_flush_desc(AwSun8iEmacState *s, @@ -470,7 +475,8 @@ static ssize_t allwinner_sun8i_emac_receive(NetClientSt= ate *nc, bytes_left -=3D desc_bytes; =20 /* Move to the next descriptor */ - s->rx_desc_curr =3D allwinner_sun8i_emac_next_desc(s, &desc, 64); + s->rx_desc_curr =3D allwinner_sun8i_emac_find_desc(s, &desc, desc.= next, + AW_SUN8I_EMAC_MIN= _PKT_SZ); if (!s->rx_desc_curr) { /* Not enough buffer space available */ s->int_sta |=3D INT_STA_RX_BUF_UA; @@ -495,10 +501,10 @@ static void allwinner_sun8i_emac_transmit(AwSun8iEmac= State *s) size_t transmitted =3D 0; static uint8_t packet_buf[2048]; =20 - s->tx_desc_curr =3D allwinner_sun8i_emac_tx_desc(s, &desc, 0); + s->tx_desc_curr =3D allwinner_sun8i_emac_tx_desc(s, &desc); =20 /* Read all transmit descriptors */ - while (s->tx_desc_curr !=3D 0) { + while (allwinner_sun8i_emac_desc_owned(&desc, 0)) { =20 /* Read from physical memory into packet buffer */ bytes =3D desc.status2 & DESC_STATUS2_BUF_SIZE_MASK; @@ -524,7 +530,7 @@ static void allwinner_sun8i_emac_transmit(AwSun8iEmacSt= ate *s) packet_bytes =3D 0; transmitted++; } - s->tx_desc_curr =3D allwinner_sun8i_emac_next_desc(s, &desc, 0); + s->tx_desc_curr =3D allwinner_sun8i_emac_next_desc(s, &desc); } =20 /* Raise transmit completed interrupt */ --=20 2.25.1