Re: Patch "x86/hyper-v: Enable PIT shutdown quirk" has been added to the 4.19-stable tree

Hi gregkh,

I love your patch! Yet something to improve:

[auto build test ERROR on tip/x86/core]
[cannot apply to v4.20-rc3 next-20181119]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/gregkh-linuxfoundation-org/Patch-x86-hyper-v-Enable-PIT-shutdown-quirk-has-been-added-to-the-4-19-stable-tree/20181120-042611
config: i386-randconfig-x019-201846 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

All errors (new ones prefixed by >>):

   arch/x86/kernel/cpu/mshyperv.c: In function 'ms_hyperv_init_platform':

quoted

arch/x86/kernel/cpu/mshyperv.c:297:2: error: 'i8253_clear_counter_on_shutdown' undeclared (first use in this function)

     i8253_clear_counter_on_shutdown = false;
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/x86/kernel/cpu/mshyperv.c:297:2: note: each undeclared identifier is reported only once for each function it appears in

vim +/i8253_clear_counter_on_shutdown +297 arch/x86/kernel/cpu/mshyperv.c

   275	
   276	#if IS_ENABLED(CONFIG_HYPERV) && defined(CONFIG_KEXEC_CORE)
   277		machine_ops.shutdown = hv_machine_shutdown;
   278		machine_ops.crash_shutdown = hv_machine_crash_shutdown;
   279	#endif
   280		mark_tsc_unstable("running on Hyper-V");
   281	
   282		/*
   283		 * Generation 2 instances don't support reading the NMI status from
   284		 * 0x61 port.
   285		 */
   286		if (efi_enabled(EFI_BOOT))
   287			x86_platform.get_nmi_reason = hv_get_nmi_reason;
   288	
   289		/*
   290		 * Hyper-V VMs have a PIT emulation quirk such that zeroing the
   291		 * counter register during PIT shutdown restarts the PIT. So it
   292		 * continues to interrupt @18.2 HZ. Setting i8253_clear_counter
   293		 * to false tells pit_shutdown() not to zero the counter so that
   294		 * the PIT really is shutdown. Generation 2 VMs don't have a PIT,
   295		 * and setting this value has no effect.
   296		 */
 > 297		i8253_clear_counter_on_shutdown = false;
   298	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation