From: "eric miao" <eric.y.miao@gmail.com>
To: "David Brownell" <david-b@pacbell.net>
Cc: "Linux Kernel list" <linux-kernel@vger.kernel.org>,
"Felipe Balbi" <felipebalbi@users.sourceforge.net>,
"Bill Gatliff" <bgat@billgatliff.com>,
"Haavard Skinnemoen" <hskinnemoen@atmel.com>,
"Andrew Victor" <andrew@sanpeople.com>,
"Tony Lindgren" <tony@atomide.com>,
"Jean Delvare" <khali@linux-fr.org>,
"Kevin Hilman" <khilman@mvista.com>,
"Paul Mundt" <lethal@linux-sh.org>,
"Ben Dooks" <ben@trinity.fluff.org>
Subject: Re: [patch/rfc 1/4] GPIO implementation framework
Date: Wed, 14 Nov 2007 14:51:22 +0800 [thread overview]
Message-ID: <f17812d70711132251l7d37042es999c079378992f3b@mail.gmail.com> (raw)
In-Reply-To: <200711132036.14927.david-b@pacbell.net>
On Nov 14, 2007 12:36 PM, David Brownell <david-b@pacbell.net> wrote:
> On Tuesday 13 November 2007, eric miao wrote:
> > Subject: [PATCH 5/5] move per GPIO "requested" to "struct gpio_desc"
> >
>
> > struct gpio_desc {
> > struct gpio_chip *chip;
> > unsigned is_out:1;
> > + unsigned requested:1;
> > +#ifdef CONFIG_DEBUG_FS
> > + const char *requested_str;
> > +#endif
>
> A better name for this would be "label", matching what's
> passed from gpio_request(). Ndls abrviatns r bd.
>
Fine.
>
> Note that this means (on typical 32-bit embedded hardware)
> twelve bytes per GPIO, which if you assume 256 GPIOs means
> an extra 3 KB static memory compared to the patch I sent.
>
Note this reduces the memory in gpio_chip, so it consumes almost same
memory as the patch you sent.
>
> > @@ -43,20 +43,19 @@ static inline int gpio_is_onchip(unsigned gpio,
> > struct gpio_chip *chip)
> > /* Warn when drivers omit gpio_request() calls -- legal but
> > * ill-advised when setting direction, and otherwise illegal.
> > */
> > -static void gpio_ensure_requested(struct gpio_chip *chip, unsigned offset)
> > +static void gpio_ensure_requested(unsigned gpio)
>
> Simpler to pass a gpio_desc pointer ...
>
>
> > if (!requested)
> > - printk(KERN_DEBUG "GPIO-%d autorequested\n",
> > - chip->base + offset);
> > + pr_debug("GPIO-%d autorequested\n", gpio);
>
> Leave the printk in ... this is the sort of thing we want
> to see fixed, which becomes unlikely once you hide such
> diagnostics. And for that matter, what would be enabling
> the "-DDEBUG" that would trigger a pr_debug() message?
>
line length issue, just ignore this if you prefer.
>
>
> ... overall the main downside of these patches seems to
> be that it consumes more static memory.
>
Not really, since it reduces the holes. That all depend on your
ARCH_NR_GPIOS.
--
Cheers
- eric
next prev parent reply other threads:[~2007-11-14 6:51 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <200710291809.29936.david-b@pacbell.net>
2007-10-30 1:51 ` [patch/rfc 1/4] GPIO implementation framework David Brownell
2007-11-05 21:05 ` David Brownell
2007-11-13 2:28 ` eric miao
2007-11-13 19:06 ` David Brownell
2007-11-14 0:57 ` eric miao
2007-11-14 1:00 ` eric miao
2007-11-14 1:02 ` eric miao
2007-11-14 1:03 ` eric miao
2007-11-14 1:04 ` eric miao
2007-11-14 1:04 ` eric miao
2007-11-14 4:36 ` David Brownell
2007-11-14 6:51 ` eric miao [this message]
2007-11-14 7:19 ` David Brownell
2007-11-14 7:36 ` eric miao
2007-11-17 10:38 ` Jean Delvare
2007-11-17 17:36 ` David Brownell
2007-11-20 15:20 ` Jean Delvare
2007-11-14 4:18 ` David Brownell
2007-11-14 6:46 ` eric miao
2007-11-14 3:28 ` David Brownell
2007-11-14 3:25 ` David Brownell
2007-11-14 3:53 ` David Brownell
2007-11-14 6:37 ` eric miao
2007-11-14 3:30 ` David Brownell
2007-11-14 6:40 ` eric miao
2007-11-14 7:08 ` David Brownell
2007-11-27 1:46 ` David Brownell
2007-11-27 10:58 ` eric miao
2007-11-27 17:26 ` David Brownell
2007-11-27 19:03 ` David Brownell
2007-11-27 19:29 ` David Brownell
2007-11-28 5:11 ` eric miao
2007-11-28 3:15 ` [patch/rfc 2.6.24-rc3-mm] gpiolib grows a gpio_desc David Brownell
2007-11-28 9:10 ` eric miao
2007-11-28 9:53 ` David Brownell
2007-10-30 1:51 ` [patch/rfc 2/4] pcf875x I2C GPIO expander driver David Brownell
2007-11-30 12:32 ` Jean Delvare
2007-11-30 13:04 ` Bill Gatliff
2007-11-30 13:36 ` Jean Delvare
2007-11-30 14:09 ` Bill Gatliff
2007-11-30 18:40 ` David Brownell
2007-11-30 20:13 ` Jean Delvare
2007-11-30 20:59 ` David Brownell
2008-04-04 2:06 ` Trent Piepho
2008-04-04 2:45 ` Ben Nizette
2008-04-04 3:33 ` Trent Piepho
2008-04-04 4:57 ` Ben Nizette
2008-04-05 4:05 ` userspace GPIO access (WAS: [patch/rfc 2/4] pcf875x ...) David Brownell
2008-04-07 17:56 ` Trent Piepho
2008-04-04 8:09 ` [patch/rfc 2/4] pcf875x I2C GPIO expander driver Jean Delvare
2008-04-04 19:07 ` Trent Piepho
2008-04-04 19:36 ` Jean Delvare
2008-04-04 20:18 ` Trent Piepho
2008-04-05 2:51 ` David Brownell
2008-04-05 2:53 ` David Brownell
2007-12-06 3:03 ` [patch/rfc 2/4] pcf857x " David Brownell
2007-12-06 23:17 ` Jean Delvare
2007-12-07 4:02 ` David Brownell
2007-10-30 1:53 ` [patch/rfc 3/4] DaVinci platform uses new GPIOLIB David Brownell
2007-10-30 1:54 ` [patch/rfc 4/4] DaVinci EVM uses pcf857x GPIO driver David Brownell
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=f17812d70711132251l7d37042es999c079378992f3b@mail.gmail.com \
--to=eric.y.miao@gmail.com \
--cc=andrew@sanpeople.com \
--cc=ben@trinity.fluff.org \
--cc=bgat@billgatliff.com \
--cc=david-b@pacbell.net \
--cc=felipebalbi@users.sourceforge.net \
--cc=hskinnemoen@atmel.com \
--cc=khali@linux-fr.org \
--cc=khilman@mvista.com \
--cc=lethal@linux-sh.org \
--cc=linux-kernel@vger.kernel.org \
--cc=tony@atomide.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
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;
as well as URLs for NNTP newsgroup(s).