linux-kernel - Re: [PATCH 1/1] gpio: altera: Use handle_level_irq when configured as a level

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 17 Feb 2017 19:32:52 +0800
From:   Phil Reid <preid@...ctromag.com.au>
To:     Andy Shevchenko <andy.shevchenko@...il.com>
Cc:     thloh@...era.com, Linus Walleij <linus.walleij@...aro.org>,
        Alexandre Courbot <gnurou@...il.com>,
        "linux-gpio@...r.kernel.org" <linux-gpio@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 1/1] gpio: altera: Use handle_level_irq when configured as
 a level_high

On 17/02/2017 17:23, Andy Shevchenko wrote:
> On Fri, Feb 17, 2017 at 11:12 AM, Phil Reid <preid@...ctromag.com.au> wrote:
>> When a threaded irq handler is chained attached to one of the gpio
>> pins when configure for level irq the altera_gpio_irq_leveL_high_handler
>> does not mask the interrupt while being handled by the chained irq.
>> This resulting in the threaded irq not getting enough cycles to complete
>> quickly enough before the irq was disabled as faulty.
>> It looks like handle_level_irq should be used in this situation
>> instead of handle_simple_irq.
>
>> @@ -310,7 +310,8 @@ static int altera_gpio_probe(struct platform_device *pdev)
>>         altera_gc->interrupt_trigger = reg;
>>
>>         ret = gpiochip_irqchip_add(&altera_gc->mmchip.gc, &altera_irq_chip, 0,
>> -               handle_simple_irq, IRQ_TYPE_NONE);
>> +               altera_gc->interrupt_trigger == IRQ_TYPE_LEVEL_HIGH ?
>> +               handle_level_irq : handle_simple_irq, IRQ_TYPE_NONE);
>
> AFAIK, handle_bad_irq() should be used here.
>
G'day Andy

Grepping drivers/gpio find a combination of
handle_simple_irq
handle_level_irq
handle_edge_irq
handle_bad_irq
used in gpiochip_irqchip_add

The ones which use handle_bad_irq call irq_set_handler_locked in their
irq_type callback to either handle_level_irq / handle_edge_irq

So I think in this case it's correct. But I'm no expert.

-- 
Regards
Phil Reid