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Message-ID: <79450f26-fc21-fdbc-50c3-00dc2c3d4967@loongson.cn>
Date:   Wed, 12 Jul 2023 17:14:32 +0800
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Subject: Re: [PATCH v3 1/2] irqchip/loongson-eiointc: Fix return value
 checking of eiointc_index
Content-Language: en-US
To:     Marc Zyngier <maz@kernel.org>
Cc:     Huacai Chen <chenhuacai@kernel.org>,
        Jiaxun Yang <jiaxun.yang@flygoat.com>,
        linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org,
        Jianmin Lv <lvjianmin@loongson.cn>,
        loongson-kernel@lists.loongnix.cn
References: <20230711120807.1805186-1-maobibo@loongson.cn>
 <20230711120807.1805186-2-maobibo@loongson.cn> <865y6pwlsm.wl-maz@kernel.org>
From:   bibo mao <maobibo@loongson.cn>
In-Reply-To: <865y6pwlsm.wl-maz@kernel.org>
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在 2023/7/12 16:56, Marc Zyngier 写道:
> On Tue, 11 Jul 2023 13:08:06 +0100,
> Bibo Mao <maobibo@loongson.cn> wrote:
>>
>> Return value of function eiointc_index is int, however it is converted
>> into uint32_t and then compared smaller than zero. This causes logic
>> problem. There is eioint initialization problem on qemu virt-machine
>> where there is only one eioint node and more than 4 vcpus. Nodemap of
>> eioint is 1, and external device intr can only be routed to vcpu 0-3, the
>> other vcpus can not response any external device interrupts and only local
>> processor interrupts like ipi/timer can work.
>>
>> Signed-off-by: Bibo Mao <maobibo@loongson.cn>
>> ---
>>  drivers/irqchip/irq-loongson-eiointc.c | 12 +++++++-----
>>  1 file changed, 7 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/irqchip/irq-loongson-eiointc.c b/drivers/irqchip/irq-loongson-eiointc.c
>> index 92d8aa28bdf5..1c5a5b59f199 100644
>> --- a/drivers/irqchip/irq-loongson-eiointc.c
>> +++ b/drivers/irqchip/irq-loongson-eiointc.c
>> @@ -144,12 +144,14 @@ static int eiointc_router_init(unsigned int cpu)
>>  	int i, bit;
>>  	uint32_t data;
>>  	uint32_t node = cpu_to_eio_node(cpu);
>> -	uint32_t index = eiointc_index(node);
>> +	int index = eiointc_index(node);
>>  
>> -	if (index < 0) {
>> -		pr_err("Error: invalid nodemap!\n");
>> -		return -1;
>> -	}
>> +	/*
>> +	 * qemu virt-machine has only one eio intc and more than four cpus
>> +	 * irq from eio can only be routed to cpu 0-3 on virt machine
>> +	 */
>> +	if (index < 0)
>> +		return 0;
>>  
>>  	if ((cpu_logical_map(cpu) % CORES_PER_EIO_NODE) == 0) {
>>  		eiointc_enable();
> 
> This sort of thing really needs a Fixes: tag.
Sure, will add Fixes tag.

I am a newbie to lkml, thanks for kindly pointing it out :)

Regards
Bibo Mao

> 
> Thanks,
> 
> 	M.
>