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Message-Id: <1570320905.3.3@crapouillou.net>
Date: Sun, 06 Oct 2019 02:15:05 +0200
From: Paul Cercueil <paul@...pouillou.net>
To: Zhou Yanjie <zhouyanjie@...o.com>
Cc: linux-mips@...r.kernel.org, linux-kernel@...r.kernel.org,
tglx@...utronix.de, paul.burton@...s.com,
gregkh@...uxfoundation.org, jason@...edaemon.net, syq@...ian.org,
marc.zyngier@....com, rfontana@...hat.com, armijn@...ldur.nl,
allison@...utok.net
Subject: Re: [PATCH 5/5 v5] irqchip: Ingenic: Add process for more than one
irq at the same time.
Le mer., oct. 2, 2019 at 19:25, Zhou Yanjie <zhouyanjie@...o.com> a
écrit :
> Add process for the situation that more than one irq is coming to
> a single chip at the same time. The original code will only respond
> to the lowest setted bit in JZ_REG_INTC_PENDING, and then exit the
> interrupt dispatch function. After exiting the interrupt dispatch
> function, since the second interrupt has not yet responded, the
> interrupt dispatch function is again entered to process the second
> interrupt. This creates additional unnecessary overhead, and the
> more interrupts that occur at the same time, the more overhead is
> added. The improved method in this patch is to check whether there
> are still unresponsive interrupts after processing the lowest
> setted bit interrupt. If there are any, the processing will be
> processed according to the bit in JZ_REG_INTC_PENDING, and the
> interrupt dispatch function will be exited until all processing
> is completed.
>
> Signed-off-by: Zhou Yanjie <zhouyanjie@...o.com>
Looks good to me.
Reviewed-by: Paul Cercueil <paul@...pouillou.net>
> ---
> drivers/irqchip/irq-ingenic.c | 17 +++++++++++------
> 1 file changed, 11 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/irqchip/irq-ingenic.c
> b/drivers/irqchip/irq-ingenic.c
> index 06ab3ad..c1be3d5 100644
> --- a/drivers/irqchip/irq-ingenic.c
> +++ b/drivers/irqchip/irq-ingenic.c
> @@ -1,7 +1,7 @@
> // SPDX-License-Identifier: GPL-2.0-or-later
> /*
> * Copyright (C) 2009-2010, Lars-Peter Clausen <lars@...afoo.de>
> - * JZ4740 platform IRQ support
> + * Ingenic XBurst platform IRQ support
> */
>
> #include <linux/errno.h>
> @@ -37,18 +37,23 @@ static irqreturn_t intc_cascade(int irq, void
> *data)
> struct ingenic_intc_data *intc = irq_get_handler_data(irq);
> struct irq_domain *domain = intc->domain;
> struct irq_chip_generic *gc;
> - uint32_t irq_reg;
> + uint32_t pending;
> unsigned i;
>
> for (i = 0; i < intc->num_chips; i++) {
> gc = irq_get_domain_generic_chip(domain, i * 32);
>
> - irq_reg = irq_reg_readl(gc, JZ_REG_INTC_PENDING);
> - if (!irq_reg)
> + pending = irq_reg_readl(gc, JZ_REG_INTC_PENDING);
> + if (!pending)
> continue;
>
> - irq = irq_find_mapping(domain, __fls(irq_reg) + (i * 32));
> - generic_handle_irq(irq);
> + while (pending) {
> + int bit = __fls(pending);
> +
> + irq = irq_find_mapping(domain, bit + (i * 32));
> + generic_handle_irq(irq);
> + pending &= ~BIT(bit);
> + }
> }
>
> return IRQ_HANDLED;
> --
> 2.7.4
>
>
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