From: Arnd Bergmann <arnd@arndb•de>
To: Anton Vorontsov <avorontsov@ru•mvista.com>
Cc: sdhci-devel@list•drzeus.cx, linux-kernel@vger•kernel.org,
Liu Dave <DaveLiu@freescale•com>,
Joe D'Abbraccio <Joe.D'abbraccio@freescale•com>,
linuxppc-dev@ozlabs•org, Konjin Lai <Konjin.Lai@freescale•com>,
Ben Dooks <ben-linux@fluff•org>,
Pierre Ossman <drzeus-sdhci@drzeus•cx>,
Xie Xiaobo <X.Xie@freescale•com>
Subject: Re: [PATCH 02/10] sdhci: Add support for bus-specific IO memory accessors
Date: Thu, 22 Jan 2009 12:55:48 +0100 [thread overview]
Message-ID: <200901221255.49724.arnd@arndb.de> (raw)
In-Reply-To: <20090122020019.GB11492@oksana.dev.rtsoft.ru>
On Thursday 22 January 2009, Anton Vorontsov wrote:
> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0/*
> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 * These accessors duplicate s=
dhci_ops, but there are two reasons for
> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 * this:
> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 * 1. sdhci_ops are const, so =
the sdhci driver won't able to assign
> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 * =C2=A0 =C2=A0default ops;
You could assign the pointer to a const default_sdhci_ops structure,
which IMHO would be cleaner than copying the function pointers
separately.
> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 * 2. Using host->X instead of=
host->ops->X saves us one dereference.
> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 * =C2=A0 =C2=A0This can be us=
eful in PIO mode. (Though the benefit of this
> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 * =C2=A0 =C2=A0is negligibly =
small).
> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 */
I doubt that this is even measurable. If it was, you could still use a copy
of that structure, like
struct sdhci_host {
...
struct sdhci_ops ops; /* not struct sdhci_ops *ops */
...
};
and do an assignment of the structure, like
static void assign_ops(struct sdhci_host *host, struct sdhci_ops *ops)
{
host->ops =3D *ops;
}
Arnd <><
next prev parent reply other threads:[~2009-01-22 11:56 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-01-22 1:56 [PATCH RFC 0/10] Freescale "eSDHC" SDHCI support (was [PATCH] mmc: Add driver for Freescale eSDHC controllers) Anton Vorontsov
2009-01-22 1:59 ` [PATCH 01/10] sdhci: Add quirk for controllers with no end-of-busy IRQ Anton Vorontsov
2009-01-22 2:00 ` [PATCH 02/10] sdhci: Add support for bus-specific IO memory accessors Anton Vorontsov
2009-01-22 11:55 ` Arnd Bergmann [this message]
2009-01-22 18:31 ` Anton Vorontsov
2009-01-22 2:00 ` [PATCH 03/10] sdhci: Add support for card-detection polling Anton Vorontsov
2009-01-22 2:00 ` [PATCH 04/10] sdhci: Add support for hosts reporting inverted write-protect state Anton Vorontsov
2009-01-22 2:00 ` [PATCH 05/10] sdhci: Add support for hosts with strict 32 bit addressing Anton Vorontsov
2009-01-22 2:00 ` [PATCH 06/10] sdhci: Add quirk to suppress PIO interrupts during DMA transfers Anton Vorontsov
2009-01-22 2:00 ` [PATCH 07/10] sdhci: Add support for hosts that don't specify clocks in the cap. register Anton Vorontsov
2009-01-22 2:00 ` [PATCH 08/10] sdhci: Add set_clock callback Anton Vorontsov
2009-01-22 2:00 ` [PATCH 09/10] sdhci: Add quirk for Freescale eSDHC controllers Anton Vorontsov
2009-01-22 2:00 ` [PATCH 10/10] mmc: Add OpenFirmware bindings for SDHCI driver Anton Vorontsov
2009-01-22 12:05 ` Arnd Bergmann
2009-01-22 19:15 ` Kumar Gala
2009-01-25 6:42 ` Matt Sealey
2009-01-26 22:26 ` M. Warner Losh
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=200901221255.49724.arnd@arndb.de \
--to=arnd@arndb$(echo .)de \
--cc=DaveLiu@freescale$(echo .)com \
--cc=Joe.D'abbraccio@freescale$(echo .)com \
--cc=Konjin.Lai@freescale$(echo .)com \
--cc=X.Xie@freescale$(echo .)com \
--cc=avorontsov@ru$(echo .)mvista.com \
--cc=ben-linux@fluff$(echo .)org \
--cc=drzeus-sdhci@drzeus$(echo .)cx \
--cc=linux-kernel@vger$(echo .)kernel.org \
--cc=linuxppc-dev@ozlabs$(echo .)org \
--cc=sdhci-devel@list$(echo .)drzeus.cx \
/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