linux-kernel - Re: [PATCH 2/3] gpio: brcmstb: implement irq_mask

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Message-ID: <cb4ef2ed-ba94-4475-b02a-5b6e39943e81@broadcom.com>
Date: Thu, 22 Jan 2026 11:17:24 -0800
From: Florian Fainelli <florian.fainelli@...adcom.com>
To: Andy Shevchenko <andy.shevchenko@...il.com>
Cc: linux-kernel@...r.kernel.org, Doug Berger <opendmb@...il.com>,
 Broadcom internal kernel review list
 <bcm-kernel-feedback-list@...adcom.com>, Linus Walleij <linusw@...nel.org>,
 Bartosz Golaszewski <brgl@...nel.org>, Christophe Leroy
 <chleroy@...nel.org>, "open list:GPIO SUBSYSTEM"
 <linux-gpio@...r.kernel.org>,
 "moderated list:BROADCOM BCM7XXX ARM ARCHITECTURE"
 <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH 2/3] gpio: brcmstb: implement irq_mask_ack



On 1/21/2026 11:36 PM, Andy Shevchenko wrote:
> On Thu, Jan 22, 2026 at 3:06 AM Florian Fainelli
> <florian.fainelli@...adcom.com> wrote:
>>
>> From: Doug Berger <opendmb@...il.com>
>>
>> The irq_mask_ack operation is slightly more efficient than doing
>> irq_mask and irq_ack separately.
> 
> I would refer to the callbacks as
> 
> .irq_mask()
> .irq_ack()
> 
> et cetera.

Ack.

> 
>> More importantly for this driver it bypasses the check of
>> irqd_irq_masked ensuring a previously masked but still active
>> interrupt gets remasked if unmasked at the hardware level. This
>> allows the driver to more efficiently unmask the wake capable
>> interrupts when quiescing without needing to enable the irqs
>> individually to clear the irqd_irq_masked state.
> 
> ...
> 
>> -// Copyright (C) 2015-2017 Broadcom
>> +// Copyright (C) 2015-2026 Broadcom
> 
> Shouldn't it be rather 2015-2017,2026 ? (In one case when I updated a
> driver for Intel, I went via Git history to gather the info.)

Ack.

> 
> ...
> 
>>   static void brcmstb_gpio_set_imask(struct brcmstb_gpio_bank *bank,
>> -               unsigned int hwirq, bool enable)
>> +               unsigned int hwirq, bool enable, bool ack)
> 
> This type of interface is usually discouraged as it makes code harder
> to read and follow. Since there are a lot of duplication, I recommend
> to move the ack op to a separate helper.

Good point, knowing the order and what set in those parameters can be 
confusing.

> 
> ...
> 
>> -       gpio_generic_write_reg(&bank->chip,
>> -                              priv->reg_base + GIO_MASK(bank->id), imask);
>> +       if (ack)
>> +               gpio_generic_write_reg(&bank->chip,
>> +                                      priv->reg_base + GIO_MASK(bank->id),
>> +                                      imask);
> 
> Id est this piece...
> 
> 
> 
>> +static void brcmstb_gpio_irq_mask_ack(struct irq_data *d)
>> +{
>> +       struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
>> +       struct brcmstb_gpio_bank *bank = gpiochip_get_data(gc);
>> +
>> +       brcmstb_gpio_set_imask(bank, d->hwirq, false, true);
> 
> ...and call it here explicitly (seems the only place for it, so it can
> even be just moved here without an intermediate helper).

Will do, thanks!
-- 
Florian