Commit ef32fef1 authored by wenglianfa's avatar wenglianfa Committed by 岳国风
Browse files

RDMA/hns: Fix CPU stuck due to read polling during reset 

driver inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I9SI44



----------------------------------------------------------------------

This read polling mostly ensures that resources such as qp are
not destroyed during hw resetting. But if the polling times out,
it doesn't work. To instead it, a mechanism for delaying resource
destruction has been introduced to fully ensure that.

Read polling wastes too much CPU time and resources causing the
cpu stuck. And the role of polling has been replaced, remove
read_poll_timeout_atomic() to fix it.

Fixes: 306b8c76 ("RDMA/hns: Do not destroy QP resources in the hw resetting phase")
Signed-off-by: default avatarwenglianfa <wenglianfa@huawei.com>
Signed-off-by: default avatarGuofeng Yue <yueguofeng@h-partners.com>
parent 1cec5deb

drivers/infiniband/hw/hns/hns_roce_hw_v2.c

+1 −10
Original line number Diff line number Diff line
@@ -33,7 +33,6 @@ 
#include <linux/acpi.h>

#include <linux/etherdevice.h>

#include <linux/interrupt.h>

#include <linux/iopoll.h>

#include <linux/kernel.h>

#include <linux/types.h>

#include <net/addrconf.h>
@@ -1146,14 +1145,9 @@ static u32 hns_roce_v2_cmd_hw_resetting(struct hns_roce_dev *hr_dev, 
					unsigned long instance_stage,

					unsigned long reset_stage)

{

#define HW_RESET_TIMEOUT_US 1000000

#define HW_RESET_DELAY_US 1



	struct hns_roce_v2_priv *priv = hr_dev->priv;

	struct hnae3_handle *handle = priv->handle;

	const struct hnae3_ae_ops *ops = handle->ae_algo->ops;

	unsigned long val;

	int ret;



	/* When hardware reset is detected, we should stop sending mailbox&cmq&

	 * doorbell to hardware. If now in .init_instance() function, we should
@@ -1166,10 +1160,7 @@ static u32 hns_roce_v2_cmd_hw_resetting(struct hns_roce_dev *hr_dev, 
	 */

	hr_dev->dis_db = true;



	ret = read_poll_timeout_atomic(ops->ae_dev_reset_cnt, val,

				val > hr_dev->reset_cnt, HW_RESET_DELAY_US,

				HW_RESET_TIMEOUT_US, false, handle);

	if (!ret)

	if (!ops->get_hw_reset_stat(handle))

		hr_dev->is_reset = true;



	if (!hr_dev->is_reset || reset_stage == HNS_ROCE_STATE_RST_INIT ||