From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 B10FA4315A; Sun, 7 Sep 2025 20:41:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757277697; cv=none; b=Ayj0PAOtERUn1jgu1uIMVfzzhBJZ0EEPO1BwQ7Lnq/nYkPvKwkN7XYt+HwMrlPpX2ZrFJ2/KSUswXtuH/2v9zwnIrN/u38YqhFSCZo2gYnOvgt2TVuWGZUtznW9j502KuRg3dJNvORxLP3d98cQoxikU1NW6zAvoyx1DEj4cWxY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757277697; c=relaxed/simple; bh=3vAkz7xOpBTqg/zJosKh7vNxFkEWqSu86inMl/LMarE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Gkmfwy5Kt1dVTEN7Gpsdvr7hRmY7Dia9d5rZV7rqbSt9SO4swaM5awyk9iNXVNaRZOhxlSUQlX7Loal0Hk/dxh2KAlOzMdmxkWctPeIamJ+i3plKkWjqqAFL8u2E4TK8e0tmxCONFfaM50LroVjhqU3VjBXiIJcuwpmM/lSurKs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=U1zKG3PT; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="U1zKG3PT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3833FC4CEF0; Sun, 7 Sep 2025 20:41:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1757277697; bh=3vAkz7xOpBTqg/zJosKh7vNxFkEWqSu86inMl/LMarE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=U1zKG3PTsub1RHH/7ry/PCdVWAbFt8tKBsrRRYXeBvZqN9n4u9kmJtEVj4/Zz6bz5 IaGiJGuPsgOqDn82LkgeUz9oXXYARpQtUHMeK6tdnbdhRVX0eJW/YpS7A22yK4UdYK zCgdtAn9zzjC+YhhYA07NcNCJTKlUyEu9gALcpdw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Vadim Fedorenko , Horatiu Vultur , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.16 095/183] phy: mscc: Stop taking ts_lock for tx_queue and use its own lock Date: Sun, 7 Sep 2025 21:58:42 +0200 Message-ID: <20250907195618.044442065@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20250907195615.802693401@linuxfoundation.org> References: <20250907195615.802693401@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Horatiu Vultur [ Upstream commit 9b2bfdbf43adb9929c5ddcdd96efedbf1c88cf53 ] When transmitting a PTP frame which is timestamp using 2 step, the following warning appears if CONFIG_PROVE_LOCKING is enabled: ============================= [ BUG: Invalid wait context ] 6.17.0-rc1-00326-ge6160462704e #427 Not tainted ----------------------------- ptp4l/119 is trying to lock: c2a44ed4 (&vsc8531->ts_lock){+.+.}-{3:3}, at: vsc85xx_txtstamp+0x50/0xac other info that might help us debug this: context-{4:4} 4 locks held by ptp4l/119: #0: c145f068 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x58/0x1440 #1: c29df974 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x5c4/0x1440 #2: c2aaaad0 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x108/0x350 #3: c2aac170 (&lan966x->tx_lock){+.-.}-{2:2}, at: lan966x_port_xmit+0xd0/0x350 stack backtrace: CPU: 0 UID: 0 PID: 119 Comm: ptp4l Not tainted 6.17.0-rc1-00326-ge6160462704e #427 NONE Hardware name: Generic DT based system Call trace: unwind_backtrace from show_stack+0x10/0x14 show_stack from dump_stack_lvl+0x7c/0xac dump_stack_lvl from __lock_acquire+0x8e8/0x29dc __lock_acquire from lock_acquire+0x108/0x38c lock_acquire from __mutex_lock+0xb0/0xe78 __mutex_lock from mutex_lock_nested+0x1c/0x24 mutex_lock_nested from vsc85xx_txtstamp+0x50/0xac vsc85xx_txtstamp from lan966x_fdma_xmit+0xd8/0x3a8 lan966x_fdma_xmit from lan966x_port_xmit+0x1bc/0x350 lan966x_port_xmit from dev_hard_start_xmit+0xc8/0x2c0 dev_hard_start_xmit from sch_direct_xmit+0x8c/0x350 sch_direct_xmit from __dev_queue_xmit+0x680/0x1440 __dev_queue_xmit from packet_sendmsg+0xfa4/0x1568 packet_sendmsg from __sys_sendto+0x110/0x19c __sys_sendto from sys_send+0x18/0x20 sys_send from ret_fast_syscall+0x0/0x1c Exception stack(0xf0b05fa8 to 0xf0b05ff0) 5fa0: 00000001 0000000e 0000000e 0004b47a 0000003a 00000000 5fc0: 00000001 0000000e 00000000 00000121 0004af58 00044874 00000000 00000000 5fe0: 00000001 bee9d420 00025a10 b6e75c7c So, instead of using the ts_lock for tx_queue, use the spinlock that skb_buff_head has. Reviewed-by: Vadim Fedorenko Fixes: 7d272e63e0979d ("net: phy: mscc: timestamping and PHC support") Signed-off-by: Horatiu Vultur Link: https://patch.msgid.link/20250902121259.3257536-1-horatiu.vultur@microchip.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/phy/mscc/mscc_ptp.c | 18 ++++++++---------- 1 file changed, 8 insertions(+), 10 deletions(-) diff --git a/drivers/net/phy/mscc/mscc_ptp.c b/drivers/net/phy/mscc/mscc_ptp.c index 72847320cb652..d692df7d975c7 100644 --- a/drivers/net/phy/mscc/mscc_ptp.c +++ b/drivers/net/phy/mscc/mscc_ptp.c @@ -456,12 +456,12 @@ static void vsc85xx_dequeue_skb(struct vsc85xx_ptp *ptp) *p++ = (reg >> 24) & 0xff; } - len = skb_queue_len(&ptp->tx_queue); + len = skb_queue_len_lockless(&ptp->tx_queue); if (len < 1) return; while (len--) { - skb = __skb_dequeue(&ptp->tx_queue); + skb = skb_dequeue(&ptp->tx_queue); if (!skb) return; @@ -486,7 +486,7 @@ static void vsc85xx_dequeue_skb(struct vsc85xx_ptp *ptp) * packet in the FIFO right now, reschedule it for later * packets. */ - __skb_queue_tail(&ptp->tx_queue, skb); + skb_queue_tail(&ptp->tx_queue, skb); } } @@ -1068,6 +1068,7 @@ static int vsc85xx_hwtstamp(struct mii_timestamper *mii_ts, case HWTSTAMP_TX_ON: break; case HWTSTAMP_TX_OFF: + skb_queue_purge(&vsc8531->ptp->tx_queue); break; default: return -ERANGE; @@ -1092,9 +1093,6 @@ static int vsc85xx_hwtstamp(struct mii_timestamper *mii_ts, mutex_lock(&vsc8531->ts_lock); - __skb_queue_purge(&vsc8531->ptp->tx_queue); - __skb_queue_head_init(&vsc8531->ptp->tx_queue); - /* Disable predictor while configuring the 1588 block */ val = vsc85xx_ts_read_csr(phydev, PROCESSOR, MSCC_PHY_PTP_INGR_PREDICTOR); @@ -1180,9 +1178,7 @@ static void vsc85xx_txtstamp(struct mii_timestamper *mii_ts, skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS; - mutex_lock(&vsc8531->ts_lock); - __skb_queue_tail(&vsc8531->ptp->tx_queue, skb); - mutex_unlock(&vsc8531->ts_lock); + skb_queue_tail(&vsc8531->ptp->tx_queue, skb); return; out: @@ -1548,6 +1544,7 @@ void vsc8584_ptp_deinit(struct phy_device *phydev) if (vsc8531->ptp->ptp_clock) { ptp_clock_unregister(vsc8531->ptp->ptp_clock); skb_queue_purge(&vsc8531->rx_skbs_list); + skb_queue_purge(&vsc8531->ptp->tx_queue); } } @@ -1571,7 +1568,7 @@ irqreturn_t vsc8584_handle_ts_interrupt(struct phy_device *phydev) if (rc & VSC85XX_1588_INT_FIFO_ADD) { vsc85xx_get_tx_ts(priv->ptp); } else if (rc & VSC85XX_1588_INT_FIFO_OVERFLOW) { - __skb_queue_purge(&priv->ptp->tx_queue); + skb_queue_purge(&priv->ptp->tx_queue); vsc85xx_ts_reset_fifo(phydev); } @@ -1591,6 +1588,7 @@ int vsc8584_ptp_probe(struct phy_device *phydev) mutex_init(&vsc8531->phc_lock); mutex_init(&vsc8531->ts_lock); skb_queue_head_init(&vsc8531->rx_skbs_list); + skb_queue_head_init(&vsc8531->ptp->tx_queue); /* Retrieve the shared load/save GPIO. Request it as non exclusive as * the same GPIO can be requested by all the PHYs of the same package. -- 2.50.1