Wei Huang
477c50e8dc
We saw perf IRQ init failures when running Linux kernel in an ACPI guest without PMU (i.e. pmu=off). This is because perf IRQ is not present when pmu=off, but arm_pmu_acpi still tries to register or unregister GSI. This patch addresses the problem by checking gicc->performance_interrupt. If it is 0, which is the value set by qemu when pmu=off, we skip the IRQ register/unregister process. [ 4.069470] bc00: 0000000000040b00 ffff0000089db190 [ 4.070267] [<ffff000008134f80>] enable_percpu_irq+0xdc/0xe4 [ 4.071192] [<ffff000008667cc4>] arm_perf_starting_cpu+0x108/0x10c [ 4.072200] [<ffff0000080cbdd4>] cpuhp_invoke_callback+0x14c/0x4ac [ 4.073210] [<ffff0000080ccd3c>] cpuhp_thread_fun+0xd4/0x11c [ 4.074132] [<ffff0000080f1394>] smpboot_thread_fn+0x1b4/0x1c4 [ 4.075081] [<ffff0000080ec90c>] kthread+0x10c/0x138 [ 4.075921] [<ffff0000080833c0>] ret_from_fork+0x10/0x50 [ 4.076947] genirq: Setting trigger mode 4 for irq 43 failed (gic_set_type+0x0/0x74) Signed-off-by: Wei Huang <wei@redhat.com> [will: add comment justifying deviation from ACPI spec, removed redundant hunk] Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.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.