988e175b9d
We replace usleep_range that was excessively long anyway with udelay to avoid using usleep_range function in spin_lock_bh spin region, thereby avoiding this calltrace: BUG: scheduling while atomic: insmod/1428/0x00000002 Modules linked in: hns-roce-hw-v2(+) hns_roce rdma_ucm rdma_cm iw_cm ib_uverbs ib_cm ib_core CPU: 0 PID: 1428 Comm: insmod Not tainted 4.12.0-rc1-00677-g252e8fd-dirty #43 Hardware name: (null) (DT) Call trace: [<ffff000008089d20>] dump_backtrace+0x0/0x274 [<ffff00000808a068>] show_stack+0x20/0x28 [<ffff00000844ea58>] dump_stack+0x94/0xb4 [<ffff0000080f975c>] __schedule_bug+0x68/0x84 [<ffff000008a988d4>] __schedule+0x5fc/0x70c [<ffff000008a98a24>] schedule+0x40/0xa4 [<ffff000008a9c6f0>] schedule_hrtimeout_range_clock+0x98/0xfc [<ffff000008a9c788>] schedule_hrtimeout_range+0x34/0x40 [<ffff000008a9c098>] usleep_range+0x6c/0x80 [<ffff000000b9ae68>] hns_roce_cmd_send+0xe4/0x264 [hns-roce-hw-v2] [<ffff000000b9b748>] hns_roce_cmd_query_hw_info+0x40/0x60 [hns-roce-hw-v2] [<ffff000000b9b790>] hns_roce_v2_profile+0x28/0x668 [hns-roce-hw-v2] [<ffff000000b6b1f4>] hns_roce_init+0x6c/0x948 [hns-roce-hw-v2] Signed-off-by: Lijun Ou <oulijun@huawei.com> Signed-off-by: Wei Hu (Xavier) <xavier.huwei@huawei.com> Signed-off-by: Shaobo Xu <xushaobo2@huawei.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.