From: Guo Ren guoren@linux.alibaba.com
stable inclusion from stable-5.10.80 commit 7930892cbd4008c353c8d397d0d3a18f8ad9f9ed bugzilla: 185821 https://gitee.com/openeuler/kernel/issues/I4L7CG
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit 69ea463021be0d159ab30f96195fb0dd18ee2272 upstream.
When using "devm_request_threaded_irq(,,,,IRQF_ONESHOT,,)" in a driver, only the first interrupt is handled, and following interrupts are never delivered (initially reported in [1]).
That's because the RISC-V PLIC cannot EOI masked interrupts, as explained in the description of Interrupt Completion in the PLIC spec [2]:
<quote> The PLIC signals it has completed executing an interrupt handler by writing the interrupt ID it received from the claim to the claim/complete register. The PLIC does not check whether the completion ID is the same as the last claim ID for that target. If the completion ID does not match an interrupt source that *is currently enabled* for the target, the completion is silently ignored. </quote>
Re-enable the interrupt before completion if it has been masked during the handling, and remask it afterwards.
[1] http://lists.infradead.org/pipermail/linux-riscv/2021-July/007441.html [2] https://github.com/riscv/riscv-plic-spec/blob/8bc15a35d07c9edf7b5d23fec97283...
Fixes: bb0fed1c60cc ("irqchip/sifive-plic: Switch to fasteoi flow") Reported-by: Vincent Pelletier plr.vincent@gmail.com Tested-by: Nikita Shubin nikita.shubin@maquefel.me Signed-off-by: Guo Ren guoren@linux.alibaba.com Cc: stable@vger.kernel.org Cc: Thomas Gleixner tglx@linutronix.de Cc: Palmer Dabbelt palmer@dabbelt.com Cc: Atish Patra atish.patra@wdc.com Reviewed-by: Anup Patel anup@brainfault.org [maz: amended commit message] Signed-off-by: Marc Zyngier maz@kernel.org Link: https://lore.kernel.org/r/20211105094748.3894453-1-guoren@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Chen Jun chenjun102@huawei.com Reviewed-by: Weilong Chen chenweilong@huawei.com Acked-by: Weilong Chen chenweilong@huawei.com
Signed-off-by: Chen Jun chenjun102@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- drivers/irqchip/irq-sifive-plic.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c index 6f432d2a5ceb..926e55d838cb 100644 --- a/drivers/irqchip/irq-sifive-plic.c +++ b/drivers/irqchip/irq-sifive-plic.c @@ -163,7 +163,13 @@ static void plic_irq_eoi(struct irq_data *d) { struct plic_handler *handler = this_cpu_ptr(&plic_handlers);
- writel(d->hwirq, handler->hart_base + CONTEXT_CLAIM); + if (irqd_irq_masked(d)) { + plic_irq_unmask(d); + writel(d->hwirq, handler->hart_base + CONTEXT_CLAIM); + plic_irq_mask(d); + } else { + writel(d->hwirq, handler->hart_base + CONTEXT_CLAIM); + } }
static struct irq_chip plic_chip = {