From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Date: Tue, 10 Sep 2013 02:34:23 +0000 Subject: Re: [BUG] simplefb not showing any output Message-Id: <522E852F.7050201@wwwdotorg.org> List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-fbdev@vger.kernel.org On 09/07/2013 06:25 AM, David Herrmann wrote: > On Sat, Sep 7, 2013 at 1:47 PM, Tom Gundersen wrote: ... >> A related question: is it expected that simplefb should be >> significantly slower than efifb, or is that something worth looking >> into? My boot with simplefb is roughly five seconds slower than with >> efifb. Coincidentally, I notice the same (or similar slowdown) with >> inteldrmfb when I see the oops (but not otherwise). > > That is probably related to the missing write-combine tag in ioremap. > Stephen, any objections to this attached patch? > Tom, if this solves the speed-issues, I will send it out once I get home. > > Thanks > David > > (Patch also attached in case of new-lines issues) > > From dbfb8e12166d494cd60823cbe84134d5d1a73ec8 Mon Sep 17 00:00:00 2001 > From: David Herrmann > Date: Sat, 7 Sep 2013 14:22:01 +0200 > Subject: [PATCH] devm/simplefb: introduce and use devm_ioremap_wc() > > We want to use devm_ioremap_nocache() or even devm_ioremap_wc() to speed > up fbdev writes _a lot_. As devm_ioremap_wc() doesn't exist, yet, > introduce it along the way. Note that ioremap_wc() is aliases to > ioremap_nocache() in asm-generic/{io,iomem}.h so we can safely expect all > architectures to either provide it or use the same alias. OK, that works fine on the Raspberry Pi too, so, Tested-by: Stephen Warren