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Date:   Thu, 21 Mar 2019 09:11:35 +0000
From:   Marc Zyngier <marc.zyngier@arm.com>
To:     chenjianguo <chenjianguo3@huawei.com>
Cc:     Thomas Gleixner <tglx@linutronix.de>,
        Jason Cooper <jason@lakedaemon.net>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "Liyou (leeyou, RTOS)" <leeyou.li@huawei.com>,
        "Joey Yan(Bo)" <joey.yanbo@huawei.com>,
        "Xiaowei (C)" <xiaowei774@huawei.com>,
        "zhanghan (Q)" <zhanghan23@huawei.com>,
        Yangyingliang <yangyingliang@huawei.com>,
        yaohongbo <yaohongbo@huawei.com>, Linuxarm <linuxarm@huawei.com>
Subject: Re: [PATCH] mbigen: don't clear eventid when free_irq
Message-ID: <20190321091135.5574b496@why.wild-wind.fr.eu.org>
In-Reply-To: <D08D06C366851D40A251D08BEEAA0F9A04367BD6@dggeml529-mbx.china.huawei.com>
References: <D08D06C366851D40A251D08BEEAA0F9A04367BD6@dggeml529-mbx.china.huawei.com>
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On Sat, 16 Mar 2019 11:15:03 +0000
chenjianguo <chenjianguo3@huawei.com> wrote:

> From: Jianguo Chen <chenjianguo3@huawei.com>
> 
> mbigen_write_msg clears eventid bits of a mbigen register
> when free a interrupt, because msi_domain_deactivate memset
> struct msg to zero. Then multiple mbigen pins with zero eventid
> will report the same interrupt number.
> 
> The eventid clear call trace:
>                 free_irq
>                 __free_irq
>                 irq_shutdown
>                 irq_domain_deactivate_irq
>                 __irq_domain_deactivate_irq
>                 __irq_domain_deactivate_irq
>                 msi_domain_deactivate
>                 platform_msi_write_msg
>                 mbigen_write_msg
> 
> Signed-off-by: Jianguo Chen <chenjianguo3@huawei.com>
> ---
>   drivers/irqchip/irq-mbigen.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/irqchip/irq-mbigen.c b/drivers/irqchip/irq-mbigen.c
> index 567b29c..fad7291 100644
> --- a/drivers/irqchip/irq-mbigen.c
> +++ b/drivers/irqchip/irq-mbigen.c
> @@ -161,6 +161,9 @@ static void mbigen_write_msg(struct msi_desc *desc,
> struct msi_msg *msg)
>         void __iomem *base = d->chip_data;
>         u32 val;
> 
> +       if (!msg->address_lo && !msg->address_hi)
> +               return;
> +
>         base += get_mbigen_vec_reg(d->hwirq);
>         val = readl_relaxed(base);
> 

For whatever reason, I couldn't apply this patch (even when fishing a
copy of this email from the archives). It seems to be corrupted is
various ways, so I had to write the patch from scratch, which is not the
most reliable way to work. Good thing this was something trivial, I
wouldn't do it for something more complicated.

In the future, please make sure to use 'git send-email' to send your
patches, as it is known to work correctly.

Thanks,

	M.
-- 
Without deviation from the norm, progress is not possible.