Messages in this thread | | | Subject | Re: [PATCH V2 net-next 08/12] net: hns3: stop schedule reset service while unloading driver | From | tanhuazhong <> | Date | Thu, 25 Apr 2019 20:04:11 +0800 |
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On 2019/4/25 19:41, Neil Horman wrote: > On Thu, Apr 25, 2019 at 02:06:07PM +0800, tanhuazhong wrote: >> >> >> On 2019/4/24 21:55, Neil Horman wrote: >>> On Wed, Apr 24, 2019 at 07:05:27PM +0800, Huazhong Tan wrote: >>>> This patch uses HCLGE_STATE_REMOVING/HCLGEVF_STATE_REMOVING flag to >>>> indicate that the driver is unloading, and we should stop new coming >>>> reset service to be scheduled, otherwise, reset service will access >>>> some resource which has been freed by unloading. >>>> >>>> Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com> >>>> Signed-off-by: Peng Li <lipeng321@huawei.com> >>>> --- >>>> V1->V2: fixes a flag setting error >>>> --- >>>> drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c | 4 +++- >>>> drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c | 4 +++- >>>> drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.h | 1 + >>>> 3 files changed, 7 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c >>>> index 4d5568e..ead8308 100644 >>>> --- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c >>>> +++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c >>>> @@ -2175,7 +2175,8 @@ static void hclge_mbx_task_schedule(struct hclge_dev *hdev) >>>> static void hclge_reset_task_schedule(struct hclge_dev *hdev) >>>> { >>>> - if (!test_and_set_bit(HCLGE_STATE_RST_SERVICE_SCHED, &hdev->state)) >>>> + if (!test_bit(HCLGE_STATE_REMOVING, &hdev->state) && >>>> + !test_and_set_bit(HCLGE_STATE_RST_SERVICE_SCHED, &hdev->state)) >>>> schedule_work(&hdev->rst_service_task); >>>> } >>> >>> In what use case do you need an extra bit for this? From my read, this work >>> task only gets scheduled from: >>> 1) Interrupt handlers >>> 2) Its own service task >>> >>> Based on the fact that you are calling cancel_work_sync(...rst_service_task) >>> from the pci teardown routine, irqs should all be disabled on your devices >>> already (meaning interrupts shouldn't schedule it), and cancel_work_sync >>> guarantees that rearming cant happen from within its own service task. >>> >>> Neil >>> >> >> Beside these two cases, when the client detects an error and requests a >> reset, it will call hclge_reset_event and schedule the reset work task to >> deal with the request. This may happen after calling >> cancel_work_sync(...rst_service_task) from the pci teardown routine. >> >> Best Regards, Huazhong >> > But that is handled from either: > 1) hns_roce_v2_msix_interrupt_abn > or > 2) hns3_nic_net_timeout > or > 3) hns3_slot_reset > > You should be protected from (1) because interrupts should be disabled before > you call cancel_work_syn. > > You should be protected from (2) because the network interface will have been > brought down first (disabling the watchdog timer for the any interfaces on this > hardware > > You should be protected from (3) because you are tearing down the pci device > anyway, and the pci subsystem should be ignoring resets > > Neil >
Yes, your analysis is right, i will remove this patch.
Thanks, Huazhong.
>>> >>> . >>> >> > > . >
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