From nobody Fri Dec 19 07:28:11 2025 Received: from bali.collaboradmins.com (bali.collaboradmins.com [148.251.105.195]) (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 C7E8E20F09C; Thu, 24 Apr 2025 08:40:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.251.105.195 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745484039; cv=none; b=WEwbQQ9/w8wp+tmvO5Cv4jtP7yeoXZy7zplpTCgOn5po0ldFXJa2G5bj+KRJAaeEqpD5iaJDijq6rpz24Tct0EK7VuulA64sz5Km+QBurm0LJ3Sj2xm7Vf43G6fVV2T4WBBkNBfA9nxpEMukW+afZzIo7G9lJBMnO25jZICrn2M= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745484039; c=relaxed/simple; bh=l9dPGwMvDj8gElRX3EvehtAe/d4UpYzyGhNZphyOZUc=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=QGuoqhA3czk2z6yfFbHqZfhsRtKzeWETA+sEQAtRmaWcwMHVFWsMlGy7TdnSsHrL77SWKe2Jx1uN9jdftJ79zW/41MOXZtk+6jlvhPmqavAuruMVWZnvQVJe0jCycPY5i3b8Fen1rMIa8wsafK2Km5bP9qdM/xr9/QMCttm19os= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b=ar9PDOY0; arc=none smtp.client-ip=148.251.105.195 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b="ar9PDOY0" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1745484035; bh=l9dPGwMvDj8gElRX3EvehtAe/d4UpYzyGhNZphyOZUc=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=ar9PDOY0M/rexfHPKKWyAYFI3VdKZi6appSJiVwBw3wfbZ0+zy9UqHSe/35cV581U 7drbipRYeSVhHHVDLE7kOKWOfn0Ta/pisicOhDVwMp8gOyyWFYo3sHktMQGTPc4rfq mChSOQMTjj+vZ2lg7UNrCkEnManx656Bqwd6sddpjoYkVTOCtU+ddXytvrirhAVimI opiEZkXjt3S76MOjk4Rbul+sZvRNisZAH7S1FvtyQOMV326rSRgBDp8kyWLqPv6Zy9 Z1kcnszAj+1s9s5SHv3gL/dKf/2FvVI0zGGggnNp8pZwGYLspce9XhkCDeDmVYkxJr ZJjW0Ey6KRY9w== Received: from yukiji.home (amontpellier-657-1-116-247.w83-113.abo.wanadoo.fr [83.113.51.247]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: laeyraud) by bali.collaboradmins.com (Postfix) with ESMTPSA id A49BC17E101A; Thu, 24 Apr 2025 10:40:34 +0200 (CEST) From: Louis-Alexis Eyraud Date: Thu, 24 Apr 2025 10:38:48 +0200 Subject: [PATCH net v2 1/2] net: ethernet: mtk-star-emac: fix spinlock recursion issues on rx/tx poll 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: quoted-printable Message-Id: <20250424-mtk_star_emac-fix-spinlock-recursion-issue-v2-1-f3fde2e529d8@collabora.com> References: <20250424-mtk_star_emac-fix-spinlock-recursion-issue-v2-0-f3fde2e529d8@collabora.com> In-Reply-To: <20250424-mtk_star_emac-fix-spinlock-recursion-issue-v2-0-f3fde2e529d8@collabora.com> To: Felix Fietkau , Sean Wang , Lorenzo Bianconi , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Matthias Brugger , AngeloGioacchino Del Regno , Biao Huang , Yinghua Pan , Bartosz Golaszewski Cc: kernel@collabora.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, Louis-Alexis Eyraud X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=ed25519-sha256; t=1745484033; l=3810; i=louisalexis.eyraud@collabora.com; s=20250113; h=from:subject:message-id; bh=l9dPGwMvDj8gElRX3EvehtAe/d4UpYzyGhNZphyOZUc=; b=KoIX2GlO4Q5JBfz87m1qsqYPtTVkGGkYO0CPRQg8RFotdR2FdoqjKXYr6QPnbJOJ4EW6TNDIj 9mjx14b0pXkBczTGHKsph9qPHo2he+EWoFSHnwjDaAqgAqckEKZi1nS X-Developer-Key: i=louisalexis.eyraud@collabora.com; a=ed25519; pk=CHFBDB2Kqh4EHc6JIqFn69GhxJJAzc0Zr4e8QxtumuM= Use spin_lock_irqsave and spin_unlock_irqrestore instead of spin_lock and spin_unlock in mtk_star_emac driver to avoid spinlock recursion occurrence that can happen when enabling the DMA interrupts again in rx/tx poll. ``` BUG: spinlock recursion on CPU#0, swapper/0/0 lock: 0xffff00000db9cf20, .magic: dead4ead, .owner: swapper/0/0, .owner_cpu: 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.15.0-rc2-next-20250417-00001-gf6a27738686c-dirty #28 PREEMPT Hardware name: MediaTek MT8365 Open Platform EVK (DT) Call trace: show_stack+0x18/0x24 (C) dump_stack_lvl+0x60/0x80 dump_stack+0x18/0x24 spin_dump+0x78/0x88 do_raw_spin_lock+0x11c/0x120 _raw_spin_lock+0x20/0x2c mtk_star_handle_irq+0xc0/0x22c [mtk_star_emac] __handle_irq_event_percpu+0x48/0x140 handle_irq_event+0x4c/0xb0 handle_fasteoi_irq+0xa0/0x1bc handle_irq_desc+0x34/0x58 generic_handle_domain_irq+0x1c/0x28 gic_handle_irq+0x4c/0x120 do_interrupt_handler+0x50/0x84 el1_interrupt+0x34/0x68 el1h_64_irq_handler+0x18/0x24 el1h_64_irq+0x6c/0x70 regmap_mmio_read32le+0xc/0x20 (P) _regmap_bus_reg_read+0x6c/0xac _regmap_read+0x60/0xdc regmap_read+0x4c/0x80 mtk_star_rx_poll+0x2f4/0x39c [mtk_star_emac] __napi_poll+0x38/0x188 net_rx_action+0x164/0x2c0 handle_softirqs+0x100/0x244 __do_softirq+0x14/0x20 ____do_softirq+0x10/0x20 call_on_irq_stack+0x24/0x64 do_softirq_own_stack+0x1c/0x40 __irq_exit_rcu+0xd4/0x10c irq_exit_rcu+0x10/0x1c el1_interrupt+0x38/0x68 el1h_64_irq_handler+0x18/0x24 el1h_64_irq+0x6c/0x70 cpuidle_enter_state+0xac/0x320 (P) cpuidle_enter+0x38/0x50 do_idle+0x1e4/0x260 cpu_startup_entry+0x34/0x3c rest_init+0xdc/0xe0 console_on_rootfs+0x0/0x6c __primary_switched+0x88/0x90 ``` Fixes: 0a8bd81fd6aa ("net: ethernet: mtk-star-emac: separate tx/rx handling= with two NAPIs") Signed-off-by: Louis-Alexis Eyraud Acked-by: Bartosz Golaszewski Reviewed-by: Maxime Chevallier --- drivers/net/ethernet/mediatek/mtk_star_emac.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/mediatek/mtk_star_emac.c b/drivers/net/et= hernet/mediatek/mtk_star_emac.c index 76f202d7f05537642ec294811ace2ad4a7eae383..23115881d8e892a622b34b593cf= 38e2c8bed4082 100644 --- a/drivers/net/ethernet/mediatek/mtk_star_emac.c +++ b/drivers/net/ethernet/mediatek/mtk_star_emac.c @@ -1163,6 +1163,7 @@ static int mtk_star_tx_poll(struct napi_struct *napi,= int budget) struct net_device *ndev =3D priv->ndev; unsigned int head =3D ring->head; unsigned int entry =3D ring->tail; + unsigned long flags; =20 while (entry !=3D head && count < (MTK_STAR_RING_NUM_DESCS - 1)) { ret =3D mtk_star_tx_complete_one(priv); @@ -1182,9 +1183,9 @@ static int mtk_star_tx_poll(struct napi_struct *napi,= int budget) netif_wake_queue(ndev); =20 if (napi_complete(napi)) { - spin_lock(&priv->lock); + spin_lock_irqsave(&priv->lock, flags); mtk_star_enable_dma_irq(priv, false, true); - spin_unlock(&priv->lock); + spin_unlock_irqrestore(&priv->lock, flags); } =20 return 0; @@ -1341,6 +1342,7 @@ static int mtk_star_rx(struct mtk_star_priv *priv, in= t budget) static int mtk_star_rx_poll(struct napi_struct *napi, int budget) { struct mtk_star_priv *priv; + unsigned long flags; int work_done =3D 0; =20 priv =3D container_of(napi, struct mtk_star_priv, rx_napi); @@ -1348,9 +1350,9 @@ static int mtk_star_rx_poll(struct napi_struct *napi,= int budget) work_done =3D mtk_star_rx(priv, budget); if (work_done < budget) { napi_complete_done(napi, work_done); - spin_lock(&priv->lock); + spin_lock_irqsave(&priv->lock, flags); mtk_star_enable_dma_irq(priv, true, false); - spin_unlock(&priv->lock); + spin_unlock_irqrestore(&priv->lock, flags); } =20 return work_done; --=20 2.49.0