From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout-03.galae.net (smtpout-03.galae.net [185.246.85.4]) (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 D38E13254BD for ; Tue, 28 Apr 2026 16:33:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.246.85.4 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777394012; cv=none; b=WpNNoNi4DbF1AA9Oui8ym/RcZLzgk9175rD5yks7NvsbOyp1r5khnWiowOchlpuhR93pBI2FY2AjoI+DSNM2MgAx15Vik+gQSLv6187LNwwL2qtK+JDPlKuKt46v5oWvTJiryNaEpNY992sjHQoxWIz6T7Q73CRqLL5ZiIScOXY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777394012; c=relaxed/simple; bh=dAGm4PiwWs80ZnheUKD2LU5YAlmFHcW8oMdB+VthDOQ=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=HsdAV41HCIMvj1FzHCsWWRTkWSNI7ZVNX2biD1azUwZCNAjvBTvTsbVXRYofU84fxSzfAtHnanPESjyhQrihfFqxMBsagsKnsxTbYuzartFFsdLmKj7kn/qDTJ6LO5F9KAdbPTw9AGM0xoqqzVL++jDBzVo41jpWGKaL2+33xmA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=tpujZFg8; arc=none smtp.client-ip=185.246.85.4 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="tpujZFg8" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-03.galae.net (Postfix) with ESMTPS id 59F1B4E42B61; Tue, 28 Apr 2026 16:33:29 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 2F420601D0; Tue, 28 Apr 2026 16:33:29 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id AFB1E10728F25; Tue, 28 Apr 2026 18:33:25 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1777394007; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=+0AqFZZvY0X0WypoYom4SAfWrYqe9FmXmaw/Ruojua0=; b=tpujZFg8P80/C/0+z6G3WGNUMBqqd6OBU/2f0bUtBrfwu9kUCAupJ15DyHo5htcWXJgFwu QJrO6pxRVobTz4UZQFXWsrheAkrB9QerOAUw617WALNUBKV9HzhklPJ2ntOsgVpzr4yVH6 P0zcZU+JCdf7Vu5yzUB70kSzjPJ6EVaNj/jA4lQcoG4Ld8xJ/6VuevqH49um+zjuvLbDiI 34rhUJEC67WWFRMPo41ivUIVMzqbT0vRkxAhLbz5aRFRPtfunoP77E0msbkSPFfB7yUJv4 Yg+6H35lIeS+Az9QtPvgzH9+BDRzeDw0uErmAVT+TQSgGL/vEYQS6YCpmcRQrw== From: =?utf-8?q?Th=C3=A9o_Lebrun?= Date: Tue, 28 Apr 2026 18:32:57 +0200 Subject: [PATCH net v2 1/4] net: macb: give reasons for Tx SKB kfree Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Message-Id: <20260428-macb-drop-tx-v2-1-647f5199d8df@bootlin.com> References: <20260428-macb-drop-tx-v2-0-647f5199d8df@bootlin.com> In-Reply-To: <20260428-macb-drop-tx-v2-0-647f5199d8df@bootlin.com> To: Nicolas Ferre , Claudiu Beznea , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Haavard Skinnemoen , Jeff Garzik Cc: Paolo Valerio , Conor Dooley , Nicolai Buchwitz , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Vladimir Kondratiev , Gregory CLEMENT , =?utf-8?q?Beno=C3=AEt_Monin?= , Tawfik Bayouk , Thomas Petazzoni , Maxime Chevallier , =?utf-8?q?Th=C3=A9o_Lebrun?= , stable@vger.kernel.org X-Mailer: b4 0.15.2 X-Last-TLS-Session-Version: TLSv1.3 Using dev_consume_skb_any() marks the drop reason as SKB_CONSUMED every time we free a Tx SKB. Instead, replace by SKB_DROP_REASON_NOT_SPECIFIED when packet has been dropped without sending. It is not precise but at least differs from SKB_CONSUMED and is used by many drivers for their error codepaths through dev_kfree_skb_{any,irq}(). Pass a reason around rather than call dev_consume_skb_any() or dev_kfree_skb_any() because macb_tx_unmap() is called for cleanup in all cases. macb_tx_error_task() is made complex because some SKBs encountered have been successfully sent. Fixes: 89e5785fc8a6 ("[PATCH] Atmel MACB ethernet driver") Cc: stable@vger.kernel.org Signed-off-by: Théo Lebrun --- drivers/net/ethernet/cadence/macb_main.c | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c index a12aa21244e8..9caae1ef52b1 100644 --- a/drivers/net/ethernet/cadence/macb_main.c +++ b/drivers/net/ethernet/cadence/macb_main.c @@ -1201,7 +1201,8 @@ static int macb_halt_tx(struct macb *bp) bp, TSR); } -static void macb_tx_unmap(struct macb *bp, struct macb_tx_skb *tx_skb, int budget) +static void macb_tx_unmap(struct macb *bp, struct macb_tx_skb *tx_skb, + int budget, enum skb_drop_reason reason) { if (tx_skb->mapping) { if (tx_skb->mapped_as_page) @@ -1214,7 +1215,7 @@ static void macb_tx_unmap(struct macb *bp, struct macb_tx_skb *tx_skb, int budge } if (tx_skb->skb) { - dev_consume_skb_any(tx_skb->skb); + dev_kfree_skb_any_reason(tx_skb->skb, reason); tx_skb->skb = NULL; } } @@ -1297,7 +1298,8 @@ static void macb_tx_error_task(struct work_struct *work) * Free transmit buffers in upper layer. */ for (tail = queue->tx_tail; tail != queue->tx_head; tail++) { - u32 ctrl; + enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; + u32 ctrl; desc = macb_tx_desc(queue, tail); ctrl = desc->ctrl; @@ -1307,7 +1309,10 @@ static void macb_tx_error_task(struct work_struct *work) if (ctrl & MACB_BIT(TX_USED)) { /* skb is set for the last buffer of the frame */ while (!skb) { - macb_tx_unmap(bp, tx_skb, 0); + /* The reason parameter is unused because it + * only matters when skb is valid. + */ + macb_tx_unmap(bp, tx_skb, 0, SKB_CONSUMED); tail++; tx_skb = macb_tx_skb(queue, tail); skb = tx_skb->skb; @@ -1326,6 +1331,7 @@ static void macb_tx_error_task(struct work_struct *work) bp->dev->stats.tx_bytes += skb->len; queue->stats.tx_bytes += skb->len; bytes += skb->len; + reason = SKB_CONSUMED; } } else { /* "Buffers exhausted mid-frame" errors may only happen @@ -1339,7 +1345,7 @@ static void macb_tx_error_task(struct work_struct *work) desc->ctrl = ctrl | MACB_BIT(TX_USED); } - macb_tx_unmap(bp, tx_skb, 0); + macb_tx_unmap(bp, tx_skb, 0, reason); } netdev_tx_completed_queue(netdev_get_tx_queue(bp->dev, queue_index), @@ -1458,7 +1464,7 @@ static int macb_tx_complete(struct macb_queue *queue, int budget) } /* Now we can safely release resources */ - macb_tx_unmap(bp, tx_skb, budget); + macb_tx_unmap(bp, tx_skb, budget, SKB_CONSUMED); /* skb is set only for the last buffer of the frame. * WARNING: at this point skb has been freed by @@ -2357,7 +2363,11 @@ static unsigned int macb_tx_map(struct macb *bp, for (i = queue->tx_head; i != tx_head; i++) { tx_skb = macb_tx_skb(queue, i); - macb_tx_unmap(bp, tx_skb, 0); + /* The reason parameter is unused, tx_skb->skb has not yet + * been assigned. Parent caller is responsible for freeing + * the SKB. + */ + macb_tx_unmap(bp, tx_skb, 0, SKB_DROP_REASON_NOT_SPECIFIED); } return -ENOMEM; -- 2.54.0