16775db613
If we issue a controller reset command during executing a FLR a hung task may be found: Call trace: __switch_to+0x158/0x1cc __schedule+0x2e8/0x85c schedule+0x7c/0x110 schedule_timeout+0x190/0x1cc __down+0x7c/0xd4 down+0x5c/0x7c hisi_sas_task_exec+0x510/0x680 [hisi_sas_main] hisi_sas_queue_command+0x24/0x30 [hisi_sas_main] smp_execute_task_sg+0xf4/0x23c [libsas] sas_smp_phy_control+0x110/0x1e0 [libsas] transport_sas_phy_reset+0xc8/0x190 [libsas] phy_reset_work+0x2c/0x40 [libsas] process_one_work+0x1dc/0x48c worker_thread+0x15c/0x464 kthread+0x160/0x170 ret_from_fork+0x10/0x18 This is a race condition which occurs when the FLR completes first. Here the host HISI_SAS_RESETTING_BIT flag out gets of sync as HISI_SAS_RESETTING_BIT is not always cleared with the hisi_hba.sem held, so now only set/unset HISI_SAS_RESETTING_BIT under hisi_hba.sem . Link: https://lore.kernel.org/r/1639579061-179473-7-git-send-email-john.garry@huawei.com Signed-off-by: Qi Liu <liuqi115@huawei.com> Signed-off-by: John Garry <john.garry@huawei.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
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.