6.6-stable review patch. If anyone has any objections, please let me know.
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From: Horatiu Vultur horatiu.vultur@microchip.com
[ 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 vadim.fedorenko@linux.dev Fixes: 7d272e63e0979d ("net: phy: mscc: timestamping and PHC support") Signed-off-by: Horatiu Vultur horatiu.vultur@microchip.com Link: https://patch.msgid.link/20250902121259.3257536-1-horatiu.vultur@microchip.c... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 1f6237705b44b..939a8a17595ef 100644 --- a/drivers/net/phy/mscc/mscc_ptp.c +++ b/drivers/net/phy/mscc/mscc_ptp.c @@ -455,12 +455,12 @@ 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;
@@ -485,7 +485,7 @@ 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); } }
@@ -1067,6 +1067,7 @@ static int vsc85xx_hwtstamp(struct mii_timestamper *mii_ts, struct ifreq *ifr) case HWTSTAMP_TX_ON: break; case HWTSTAMP_TX_OFF: + skb_queue_purge(&vsc8531->ptp->tx_queue); break; default: return -ERANGE; @@ -1091,9 +1092,6 @@ static int vsc85xx_hwtstamp(struct mii_timestamper *mii_ts, struct ifreq *ifr)
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); @@ -1179,9 +1177,7 @@ 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: @@ -1547,6 +1543,7 @@ 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); } }
@@ -1570,7 +1567,7 @@ 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); }
@@ -1590,6 +1587,7 @@ 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.