From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Date: Thu, 24 Mar 2016 22:13:32 -0600 Subject: [U-Boot] [PATCH v2 0/5] Enable caches for the RPi2 In-Reply-To: <1458139284-86132-1-git-send-email-agraf@suse.de> References: <1458139284-86132-1-git-send-email-agraf@suse.de> Message-ID: <56F4BAEC.9080204@wwwdotorg.org> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 03/16/2016 08:41 AM, Alexander Graf wrote: > This patch set converts the Raspberry Pi 2 system to properly make use of > the caches available in it. > > Because we're running in HYP mode, we first need to teach U-Boot how to > make use of HYP registers and the LPAE page layout which is mandated by > hardware when running in HYP mode. > > Then while we're at it, also mark the frame buffer cached to speed up > screen updates. > > With this patch set, my Raspberry Pi 3 running in AArch32 mode is a *lot* > faster than without. > > Please verify that the code works on a RPi2 as well and doesn't break the > original Pi. In theory it should work, but I only have a 3 to test on > available here. I did find one quirk with this series (as tested in my rpi_dev branch on github): HDMI console scrolling is now extremely fast for 32-bit builds. However, it's noticeably slower on the 64-bit RPi 3 build. I wonder if the DCACHE_* constants aren't optimal for AArch64? Perhaps this can all be explained instead by RPi 3 needing a slower core clock to support a fixed mini UART frequency; that probably slows down the ARM access to DRAM.