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Subject: Re: [PATCH v4 2/2] PCI: Rockchip: Add Rockchip PCIe controller
 support
To: Marc Zyngier <marc.zyngier@arm.com>, Bjorn Helgaas <bhelgaas@google.com>
References: <1467336290-11282-1-git-send-email-shawn.lin@rock-chips.com>
 <1467336290-11282-2-git-send-email-shawn.lin@rock-chips.com>
 <577646D3.7040207@arm.com>
Cc: shawn.lin@rock-chips.com, linux-pci@vger.kernel.org,
        Arnd Bergmann <arnd@arndb.de>, linux-kernel@vger.kernel.org,
        linux-rockchip@lists.infradead.org, Heiko Stuebner <heiko@sntech.de>,
        Doug Anderson <dianders@chromium.org>,
        Wenrui Li <wenrui.li@rock-chips.com>, Rob Herring <robh+dt@kernel.org>,
        devicetree@vger.kernel.org, Brian Norris <briannorris@chromium.org>
From: Shawn Lin <shawn.lin@rock-chips.com>
Message-ID: <dcb37af0-89c5-ec37-5ace-7e4df61724a5@rock-chips.com>
Date: Tue, 5 Jul 2016 10:08:08 +0800
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在 2016/7/1 18:32, Marc Zyngier 写道:
> On 01/07/16 02:24, Shawn Lin wrote:
>> This patch adds Rockchip PCIe controller support found
>> on RK3399 Soc platform.
>>
>> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
>>
>> ---
>
> [...]
>
>> +static void rockchip_pcie_legacy_int_handler(struct irq_desc *desc)
>> +{
>> +	struct irq_chip *chip = irq_desc_get_chip(desc);
>> +	struct rockchip_pcie_port *port;
>> +	u32 reg;
>> +
>> +	chained_irq_enter(chip, desc);
>> +	port = irq_desc_get_handler_data(desc);
>> +
>> +	reg = pcie_read(port, PCIE_CLIENT_INT_STATUS);
>> +	reg = (reg & ROCKCHIP_PCIE_RPIFR1_INTR_MASK) >>
>> +	       ROCKCHIP_PCIE_RPIFR1_INTR_SHIFT;
>> +	if (reg)
>> +		generic_handle_irq(irq_find_mapping(port->irq_domain,
>> +						    ffs(reg)));
>
> Can't you get multiple pending interrupts at the same time? Here, you
> seem to only process one interrupt at a time, which is going to be
> pretty inefficient.
>

Yup, will fix it, thanks.

> How about something like:
>
> 	while (reg) {
> 		int hwirq = ffs(reg);
> 		int irq;
> 		
> 		reg &= ~BIT(hwirq);
> 		irq = irq_find_mapping(port->irq_domain, hwirq);
> 		if (irq)
> 			generic_handle_irq(irq);
> 	}
>
>> +	chained_irq_exit(chip, desc);
>> +}
>> +
>
> Thanks,
>
> 	M.
>


-- 
Best Regards
Shawn Lin