On Fri, 03 Oct 2014 10:04:29 +0200 Hans de Goede <hdego...@redhat.com> wrote:
> Hi, > > On 10/01/2014 07:43 PM, Hendrik wrote: > > I have always been using the sunxi u-boot from > > 'https://github.com/linux-sunxi/u-boot-sunxi' and that works fine, but now > > I want to boot the kernel from USB. That is not possible in that u-boot > > branch. Therefore I switched to the latest U-Boot > > 'git://git.denx.de/u-boot.git' for the Olimex Allwinner A10 Lime as this > > one does have a working USB mass storage implementation. > > > > But when the kernel and root filesystem is booted and my application (using > > DirectFB) starts, the LCD screen is flickering between a correct image and > > an incorrect image as if sometimes random image data is displayed to the > > screen. Although it looks more like a clock or timing issue because the > > colors of the faulty screen resemble the colors of the correct screen. > > Also: when the cpu is inactive the screen is more or less ok but when doing > > a lot of work the screen starts to flicker. Then it is stable for a while > > and after some time it starts flickering again. > > > > I am using the exact same kernel, root filesystem, U-boot environment, > > SD-card and 'script.bin' (which defines the hardware layout, I am not using > > a device tree file). The only difference is the version (and origin) of > > U-boot. > > > > Can anybody shine some light on this? Maybe Hans de Goede? I have seen his > > name pop-up a lot of times with the Sunxi branch. > > Hmm, the only thing I can think of which may have caused this are the > recent DRAM controller code cleanups which are in upstream u-boot and > not in https://github.com/linux-sunxi/u-boot-sunxi > > Can you try copying these 2 files: > > arch/arm/cpu/armv7/sunxi/dram.c > arch/arm/include/asm/arch-sunxi/dram.h > > From https://github.com/linux-sunxi/u-boot-sunxi over into upstream > u-boot, essentially reverting the DRAM cleanup patches, and see if that > fixes things ? It is most definitely the PLL5P clock speed problem and it can be resolved by either reverting the following patch in u-boot http://git.denx.de/?p=u-boot.git;a=commit;h=013f2d746955147439215a4939655c9ed6bdd866 or by fixing a bunch of hardcoded divisors in the sunxi-3.4 kernel (for which I'll send a patch to the linux-sunxi mailing list later today). Please note that you can't use the sunxi-3.4 kernel with the unmodified mainline u-boot anyway because of the missing machine id definitions and the new PSCI code (but this is a problem only on Allwinner A20 hardware). A few minor patches are needed here and there. A feature complete u-boot branch with extra patches on top of u-boot v2014.10 (for example, with HDMI video driver support) and the sunxi-3.4 kernel compatibility tweaks is going to be available shortly after the u-boot v2014.10 release. -- Best regards, Siarhei Siamashka _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
