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From: Pavel Machek <pavel@ucw.cz>
To: Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>
Cc: Tomi Valkeinen <tomi.valkeinen-l0cyMroinI0@public.gmane.org>,
	Geert Uytterhoeven
	<geert-Td1EMuHUCqxL1ZNQvxDV9g@public.gmane.org>,
	Marek Vasut <marek.vasut-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	kernel list
	<linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	Dinh Nguyen <dinh.linux-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	Jean-Christophe PLAGNIOL-VILLARD
	<plagnioj-sclMFOaUSTBWk0Htik3J/w@public.gmane.org>,
	Grant Likely
	<grant.likely-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>,
	Rob Herring <robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	Jingoo Han <jg1.han-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>,
	Rob Clark <robdclark-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	Linux Fbdev development list
	<linux-fbdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	"devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
	<devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	shc_work-JGs/UdohzUI@public.gmane.org,
	linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org,
	hsweeten-3FF4nKcrg1dE2c76skzGb0EOCMrvLtNR@public.gmane.org,
	Archit Taneja <architt-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
Subject: Re: simple framebuffer slower by factor of 20, on socfpga (arm) platform
Date: Fri, 24 Apr 2015 13:31:24 +0000	[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
     [not found]         ` <552663C2.70308-l0cyMroinI0@public.gmane.org>
2015-04-09 19:51           ` Arnd Bergmann
2015-04-24 13:31             ` Pavel Machek [this message]
2015-04-10  7:17         ` 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
     [not found]                   ` <20150428134848.GC12732-l+eeeJia6m9vn6HldHNs0ANdhmdF6hFW@public.gmane.org>
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

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