From 978749617bc0b5355e659cbeb855f7bcdc3b40ea Mon Sep 17 00:00:00 2001 From: Heiner Kallweit Date: Sun, 10 Feb 2019 15:26:07 +0100 Subject: [PATCH 1/2] Revert "r8169: remove unneeded mmiowb barriers" This reverts commit bd7153bd83b806bfcc2e79b7a6f43aa653d06ef3. There doesn't seem to be anything wrong with this patch, it's just reverted to get a stable baseline again. Signed-off-by: Heiner Kallweit Signed-off-by: David S. Miller --- drivers/net/ethernet/realtek/r8169.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c index abb94c543aa2ba..bba806ce57d35d 100644 --- a/drivers/net/ethernet/realtek/r8169.c +++ b/drivers/net/ethernet/realtek/r8169.c @@ -1286,11 +1286,13 @@ static u16 rtl_get_events(struct rtl8169_private *tp) static void rtl_ack_events(struct rtl8169_private *tp, u16 bits) { RTL_W16(tp, IntrStatus, bits); + mmiowb(); } static void rtl_irq_disable(struct rtl8169_private *tp) { RTL_W16(tp, IntrMask, 0); + mmiowb(); } #define RTL_EVENT_NAPI_RX (RxOK | RxErr) @@ -6130,8 +6132,10 @@ static netdev_tx_t rtl8169_start_xmit(struct sk_buff *skb, if (unlikely(stop_queue)) netif_stop_queue(dev); - if (__netdev_sent_queue(dev, skb->len, skb->xmit_more)) + if (__netdev_sent_queue(dev, skb->len, skb->xmit_more)) { RTL_W8(tp, TxPoll, NPQ); + mmiowb(); + } if (unlikely(stop_queue)) { /* Sync with rtl_tx: @@ -6483,7 +6487,9 @@ static int rtl8169_poll(struct napi_struct *napi, int budget) if (work_done < budget) { napi_complete_done(napi, work_done); + rtl_irq_enable(tp); + mmiowb(); } return work_done; From 0255d5927c0f2484de2649c7eb69e4fc459f0130 Mon Sep 17 00:00:00 2001 From: Heiner Kallweit Date: Sun, 10 Feb 2019 15:28:04 +0100 Subject: [PATCH 2/2] Revert "r8169: make use of xmit_more and __netdev_sent_queue" This reverts commit 2e6eedb4813e34d8d84ac0eb3afb668966f3f356. Sander reported a regression causing a kernel panic[1], therefore let's revert this commit. [1] https://marc.info/?t=154965066400001&r=1&w=2 Signed-off-by: Heiner Kallweit Signed-off-by: David S. Miller --- drivers/net/ethernet/realtek/r8169.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c index bba806ce57d35d..6e36b88ca7c9c2 100644 --- a/drivers/net/ethernet/realtek/r8169.c +++ b/drivers/net/ethernet/realtek/r8169.c @@ -6074,7 +6074,6 @@ static netdev_tx_t rtl8169_start_xmit(struct sk_buff *skb, struct device *d = tp_to_dev(tp); dma_addr_t mapping; u32 opts[2], len; - bool stop_queue; int frags; if (unlikely(!rtl_tx_slots_avail(tp, skb_shinfo(skb)->nr_frags))) { @@ -6116,6 +6115,8 @@ static netdev_tx_t rtl8169_start_xmit(struct sk_buff *skb, txd->opts2 = cpu_to_le32(opts[1]); + netdev_sent_queue(dev, skb->len); + skb_tx_timestamp(skb); /* Force memory writes to complete before releasing descriptor */ @@ -6128,16 +6129,16 @@ static netdev_tx_t rtl8169_start_xmit(struct sk_buff *skb, tp->cur_tx += frags + 1; - stop_queue = !rtl_tx_slots_avail(tp, MAX_SKB_FRAGS); - if (unlikely(stop_queue)) - netif_stop_queue(dev); + RTL_W8(tp, TxPoll, NPQ); - if (__netdev_sent_queue(dev, skb->len, skb->xmit_more)) { - RTL_W8(tp, TxPoll, NPQ); - mmiowb(); - } + mmiowb(); - if (unlikely(stop_queue)) { + if (!rtl_tx_slots_avail(tp, MAX_SKB_FRAGS)) { + /* Avoid wrongly optimistic queue wake-up: rtl_tx thread must + * not miss a ring update when it notices a stopped queue. + */ + smp_wmb(); + netif_stop_queue(dev); /* Sync with rtl_tx: * - publish queue status and cur_tx ring index (write barrier) * - refresh dirty_tx ring index (read barrier).