This is a note to let you know that I've just added the patch titled net: hns3: use appropriate barrier function after setting a bit value to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-hns3-use-appropriate-barrier-function-after-sett.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit dfcd36f19534b56a7cd37d52636aeb28f18054a0 Author: Peiyang Wang <wangpeiyang1@xxxxxxxxxx> Date: Tue May 7 21:42:22 2024 +0800 net: hns3: use appropriate barrier function after setting a bit value [ Upstream commit 094c281228529d333458208fd02fcac3b139d93b ] There is a memory barrier in followed case. When set the port down, hclgevf_set_timmer will set DOWN in state. Meanwhile, the service task has different behaviour based on whether the state is DOWN. Thus, to make sure service task see DOWN, use smp_mb__after_atomic after calling set_bit(). CPU0 CPU1 ========================== =================================== hclgevf_set_timer_task() hclgevf_periodic_service_task() set_bit(DOWN,state) test_bit(DOWN,state) pf also has this issue. Fixes: ff200099d271 ("net: hns3: remove unnecessary work in hclgevf_main") Fixes: 1c6dfe6fc6f7 ("net: hns3: remove mailbox and reset work in hclge_main") Signed-off-by: Peiyang Wang <wangpeiyang1@xxxxxxxxxx> Signed-off-by: Jijie Shao <shaojijie@xxxxxxxxxx> Reviewed-by: Simon Horman <horms@xxxxxxxxxx> Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c index c14c391a0cec6..5dbee850fef53 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c +++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c @@ -7005,8 +7005,7 @@ static void hclge_set_timer_task(struct hnae3_handle *handle, bool enable) /* Set the DOWN flag here to disable link updating */ set_bit(HCLGE_STATE_DOWN, &hdev->state); - /* flush memory to make sure DOWN is seen by service task */ - smp_mb__before_atomic(); + smp_mb__after_atomic(); /* flush memory to make sure DOWN is seen by service task */ hclge_flush_link_update(hdev); } } diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c b/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c index 2bb0ce1761fb0..be41117ec1465 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c +++ b/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c @@ -2583,8 +2583,7 @@ static void hclgevf_set_timer_task(struct hnae3_handle *handle, bool enable) } else { set_bit(HCLGEVF_STATE_DOWN, &hdev->state); - /* flush memory to make sure DOWN is seen by service task */ - smp_mb__before_atomic(); + smp_mb__after_atomic(); /* flush memory to make sure DOWN is seen by service task */ hclgevf_flush_link_update(hdev); } }