234901de2b
The init_systime() may be invoked in atomic state. We have observed the following call trace when running "phc_ctl /dev/ptp0 set" on a Intel Agilex board. BUG: sleeping function called from invalid context at drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c:74 in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 381, name: phc_ctl preempt_count: 1, expected: 0 RCU nest depth: 0, expected: 0 Preemption disabled at: [<ffff80000892ef78>] stmmac_set_time+0x34/0x8c CPU: 2 PID: 381 Comm: phc_ctl Not tainted 5.18.0-rc2-next-20220414-yocto-standard+ #567 Hardware name: SoCFPGA Agilex SoCDK (DT) Call trace: dump_backtrace.part.0+0xc4/0xd0 show_stack+0x24/0x40 dump_stack_lvl+0x7c/0xa0 dump_stack+0x18/0x34 __might_resched+0x154/0x1c0 __might_sleep+0x58/0x90 init_systime+0x78/0x120 stmmac_set_time+0x64/0x8c ptp_clock_settime+0x60/0x9c pc_clock_settime+0x6c/0xc0 __arm64_sys_clock_settime+0x88/0xf0 invoke_syscall+0x5c/0x130 el0_svc_common.constprop.0+0x4c/0x100 do_el0_svc+0x7c/0xa0 el0_svc+0x58/0xcc el0t_64_sync_handler+0xa4/0x130 el0t_64_sync+0x18c/0x190 So we should use readl_poll_timeout_atomic() here instead of readl_poll_timeout(). Also adjust the delay time to 10us to fix a "__bad_udelay" build error reported by "kernel test robot <lkp@intel.com>". I have tested this on Intel Agilex and NXP S32G boards, there is no delay needed at all. So the 10us delay should be long enough for most cases. Fixes: ff8ed737860e ("net: stmmac: use readl_poll_timeout() function in init_systime()") Signed-off-by: Kevin Hao <haokexin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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.