On Mon, Nov 27, 2017 at 5:14 PM, Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> wrote: > On 11/27/2017 02:18 AM, Ingo Molnar wrote: >> [ 0.031000] Call Trace: >> [ 0.031000] ? kernfs_add_one+0x1d9/0x1f0 >> [ 0.031000] early_memremap+0x33/0x3d >> [ 0.031000] ? cnb20le_res+0x2f2/0x2f2 >> [ 0.031000] __acpi_map_table+0x1d/0x28 >> [ 0.031000] acpi_os_map_iomem+0x1cf/0x2a0 >> [ 0.031000] ? cnb20le_res+0x2f2/0x2f2 >> [ 0.031000] acpi_os_map_memory+0xd/0x20 >> [ 0.031000] acpi_find_root_pointer+0x1f/0x1ec >> [ 0.031000] ? cnb20le_res+0x2f2/0x2f2 >> [ 0.031000] acpi_os_get_root_pointer+0x18/0x25 >> [ 0.031000] broadcom_postcore_init+0xc/0x6c >> [ 0.031000] do_one_initcall+0xc4/0x1f7 >> [ 0.031000] kernel_init_freeable+0x1c2/0x2b2 >> [ 0.031000] ? rest_init+0x1a0/0x1a0 >> [ 0.031000] kernel_init+0xd/0x1bc >> [ 0.031000] ret_from_fork+0x1f/0x30 > > I've been able to reproduce this. The bug here (at least on my system) > is that we're calling into the ACPI code while 'acpi_disabled=1'. The > ACPI code then notices that it hasn't been initialized (because it > should be off) and calls into the early_ioremap() code thinking that > it's in early boot. > > I don't know why the bisect pinned this on the kaiser patches, or why > it's only showing up now. It's possible that some botched TLB flush > _caused_ ACPI to get disabled at a weird time which then caused this > warning. > > There are some recent changes around broadcom_postcore_init(). > > ACPI folks, any suggestions on what to do here? Should we be bailing > out of acpi_os_get_root_pointer() like the attached patch? No, the bug is in broadcom_postcore_init(), everything else should be fine. I'm not even sure why acpi_os_get_root_pointer() is called from there in the first place. It should only be called from the ACPICA code. Thanks, Rafael
