On 2022-05-06, Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> wrote: > The Amlogic Meson related issue has been investigated and fixed: > > https://lore.kernel.org/all/b7c81f02-039e-e877-d7c3-6834728d2117@xxxxxxxxxxx/ > > but I just found that there is one more issue. > > It appears on QCom-based DragonBoard 410c SBC > (arch/arm64/boot/dts/qcom/apq8016-sbc.dts). To see it on today's linux > next-20220506, one has to revert > 42cd402b8fd4672b692400fe5f9eecd55d2794ac, otherwise lockdep triggers > other warning and it is turned off too early: > > ================================ > WARNING: inconsistent lock state > 5.18.0-rc5-next-20220506+ #11869 Not tainted > -------------------------------- > inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage. > swapper/0/0 [HC1[1]:SC0[0]:HE0:SE1] takes: > ffff80000aaa8478 (&port_lock_key){?.+.}-{2:2}, at: msm_uart_irq+0x38/0x750 > {HARDIRQ-ON-W} state was registered at: > lock_acquire.part.0+0xe0/0x230 > lock_acquire+0x68/0x84 > _raw_spin_lock+0x5c/0x80 > __msm_console_write+0x1ac/0x220 > msm_console_write+0x48/0x60 > __console_emit_next_record+0x188/0x420 > printk_kthread_func+0x3a0/0x3bc > kthread+0x118/0x11c > ret_from_fork+0x10/0x20 > irq event stamp: 12182 > hardirqs last enabled at (12181): [<ffff800008e3d2a8>] > cpuidle_enter_state+0xc4/0x30c > > stack backtrace: > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.18.0-rc5-next-20220506+ #11869 > Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT) > Call trace: > dump_backtrace.part.0+0xd0/0xe0 > show_stack+0x18/0x6c > dump_stack_lvl+0x8c/0xb8 > dump_stack+0x18/0x34 > print_usage_bug.part.0+0x208/0x22c > mark_lock+0x710/0x954 > __lock_acquire+0x9fc/0x20cc > lock_acquire.part.0+0xe0/0x230 > lock_acquire+0x68/0x84 > _raw_spin_lock_irqsave+0x80/0xcc > msm_uart_irq+0x38/0x750 > __handle_irq_event_percpu+0xac/0x3d0 > handle_irq_event+0x4c/0x120 > handle_fasteoi_irq+0xa4/0x1a0 > generic_handle_domain_irq+0x3c/0x60 > gic_handle_irq+0x44/0xc4 > call_on_irq_stack+0x2c/0x54 > do_interrupt_handler+0x80/0x84 > el1_interrupt+0x34/0x64 > el1h_64_irq_handler+0x18/0x24 > el1h_64_irq+0x64/0x68 > cpuidle_enter_state+0xcc/0x30c > cpuidle_enter+0x38/0x50 > do_idle+0x22c/0x2bc > cpu_startup_entry+0x28/0x30 > rest_init+0x110/0x190 > arch_post_acpi_subsys_init+0x0/0x18 > start_kernel+0x6c4/0x704 > __primary_switched+0xc0/0xc8 > INIT: version 2.88 booting > [info] Using makefile-style concurrent boot in runlevel S. The console write() callback for the msm driver (__msm_console_write) assumes interrupts are off and is doing a spin_lock(&port->lock) rather than spin_lock_irqsave(&port->lock, flags). The following change should address the issue: John diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c index 23c94b927776..ab3f360bd354 100644 --- a/drivers/tty/serial/msm_serial.c +++ b/drivers/tty/serial/msm_serial.c @@ -1599,6 +1599,7 @@ static inline struct uart_port *msm_get_port_from_line(unsigned int line) static void __msm_console_write(struct uart_port *port, const char *s, unsigned int count, bool is_uartdm) { + unsigned long flags; int i; int num_newlines = 0; bool replaced = false; @@ -1621,7 +1622,7 @@ static void __msm_console_write(struct uart_port *port, const char *s, else if (oops_in_progress) locked = spin_trylock(&port->lock); else - spin_lock(&port->lock); + spin_lock_irqsave(&port->lock, flags); if (is_uartdm) msm_reset_dm_count(port, count); @@ -1660,7 +1661,7 @@ static void __msm_console_write(struct uart_port *port, const char *s, } if (locked) - spin_unlock(&port->lock); + spin_unlock_irqrestore(&port->lock, flags); } static void msm_console_write(struct console *co, const char *s,
