public inbox for linux-arm-kernel@lists.infradead.org 
 help / color / mirror / Atom feed
From: stigge@antcom•de (Roland Stigge)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 3/6 v9] gpio: Add userland device interface to block GPIO
Date: Wed, 05 Dec 2012 23:20:57 +0100	[thread overview]
Message-ID: <50BFC8C9.5070504@antcom.de> (raw)
In-Reply-To: <50BF99F3.4060207@grandegger.com>

Hi Wolfgang,

On 05/12/12 20:01, Wolfgang Grandegger wrote:
>> +	for (i = 0; i < block->ngpio; i++) {
>> +		status = gpio_request(block->gpio[i], "gpioblock dev");
> 
> You could use the name of the GPIO block.

OK.

>> +		if (status)
>> +			goto err1;
>> +
>> +		irq = gpio_to_irq(block->gpio[i]);
>> +		if (irq >= 0 &&
>> +		    !test_bit(FLAG_IS_OUT, &gpio_desc[block->gpio[i]].flags) &&
>> +		    !gpio_block_is_irq_duplicate(block, i)) {
>> +			status = request_irq(irq, gpio_block_irq_handler,
>> +					     IRQF_TRIGGER_FALLING,
>> +					     block->name, block);
>> +			if (status)
>> +				goto err2;
>> +
>> +			block->irq_controlled = true;
>> +		}
>> +	}
> 
> There is no need to request IRQs if "O_NONBLOCK" is specified.

Sure? Regarding this, I found: "The poll() function shall not be
affected by the O_NONBLOCK flag." [1]

> I observed that the read returns once immediately (without blocking)
> after reboot. I did not look into that yet.

Didn't happen to me. Can you tell how this can be reproduced?

Thanks,

Roland


[1] http://pubs.opengroup.org/onlinepubs/009695399/functions/poll.html

  reply	other threads:[~2012-12-05 22:20 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-12-04 20:39 [PATCH 0/6 v9] gpio: Add block GPIO Roland Stigge
2012-12-04 20:39 ` [PATCH 1/6 v9] gpio: Add a block GPIO API to gpiolib Roland Stigge
2012-12-04 20:39 ` [PATCH 2/6 v9] gpio: Add sysfs support to block GPIO API Roland Stigge
2012-12-04 20:39 ` [PATCH 3/6 v9] gpio: Add userland device interface to block GPIO Roland Stigge
2012-12-05 19:01   ` Wolfgang Grandegger
2012-12-05 22:20     ` Roland Stigge [this message]
2012-12-06  7:28       ` Wolfgang Grandegger
2012-12-04 20:39 ` [PATCH 4/6 v9] gpiolib: Fix default attributes for class Roland Stigge
2012-12-04 20:39 ` [PATCH 5/6 v9] gpio: Add device tree support to block GPIO API Roland Stigge
2012-12-04 20:39 ` [PATCH 6/6 v9] gpio: Add block gpio to several gpio drivers Roland Stigge

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=50BFC8C9.5070504@antcom.de \
    --to=stigge@antcom$(echo .)de \
    --cc=linux-arm-kernel@lists$(echo .)infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox