public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Pavel Machek <pavel@ucw.cz>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	Marek Vasut <marek.vasut@gmail.com>,
	kernel list <linux-kernel@vger.kernel.org>,
	Dinh Nguyen <dinh.linux@gmail.com>,
	Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>,
	Grant Likely <grant.likely@linaro.org>,
	Rob Herring <robh+dt@kernel.org>,
	Jingoo Han <jg1.han@samsung.com>, Rob Clark <robdclark@gmail.com>,
	Linux Fbdev development list <linux-fbdev@vger.kernel.org>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	shc_work@mail.ru, linux@arm.linux.org.uk,
	hsweeten@visionengravers.com,
	Archit Taneja <architt@codeaurora.org>
Subject: Re: simple framebuffer slower by factor of 20, on socfpga (arm) platform
Date: Fri, 24 Apr 2015 15:31:24 +0200	[thread overview]
Message-ID: <20150424133124.GB11729@amd> (raw)
In-Reply-To: <2137270.OOdtDiT2H4@wuerfel>


> > The difference is probably caused by memcpy() vs memcpy_fromio(). The
> > comment above memcpy_fromio() says "This needs to be optimized". I think
> > generally speaking memcpy_fromio() is correct for a framebuffer.
> > 
> > That said, if the fb is in RAM, and is only written by the CPU, I think
> > a normal memcpy() for fb_memcpy_fromfb() should be fine...
> 
> Could memcpy() cause alignment traps here if the fb pointer is unaligned
> and uncached?

Original commit did not comment on any failure, so I expect that is
not a problem here...
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

  reply	other threads:[~2015-04-24 13:31 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-04-07 12:12 simple framebuffer slower by factor of 20, on socfpga (arm) platform Pavel Machek
2015-04-07 12:19 ` Geert Uytterhoeven
2015-04-07 14:24   ` Marek Vasut
2015-04-09 11:06   ` Pavel Machek
2015-04-09 11:21     ` Tomi Valkeinen
2015-04-09 11:34       ` Tomi Valkeinen
2015-04-09 19:51         ` Arnd Bergmann
2015-04-24 13:31           ` Pavel Machek [this message]
2015-04-10  7:05         ` Archit Taneja
2015-04-24 13:29           ` Pavel Machek
2015-04-24 13:40             ` Tomi Valkeinen
2015-04-24 13:46               ` Geert Uytterhoeven
2015-04-26 19:31                 ` Pavel Machek
2015-04-28 13:48                 ` Russell King - ARM Linux
2015-04-28 15:28                   ` Nicolas Pitre
2015-05-06 10:45                     ` Russell King - ARM Linux
2015-05-06 20:32                       ` Nicolas Pitre
2015-05-12  8:52                       ` Pavel Machek

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=20150424133124.GB11729@amd \
    --to=pavel@ucw.cz \
    --cc=architt@codeaurora.org \
    --cc=arnd@arndb.de \
    --cc=devicetree@vger.kernel.org \
    --cc=dinh.linux@gmail.com \
    --cc=geert@linux-m68k.org \
    --cc=grant.likely@linaro.org \
    --cc=hsweeten@visionengravers.com \
    --cc=jg1.han@samsung.com \
    --cc=linux-fbdev@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@arm.linux.org.uk \
    --cc=marek.vasut@gmail.com \
    --cc=plagnioj@jcrosoft.com \
    --cc=robdclark@gmail.com \
    --cc=robh+dt@kernel.org \
    --cc=shc_work@mail.ru \
    --cc=tomi.valkeinen@ti.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