From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Nelson Date: Sat, 22 Sep 2012 08:35:38 -0700 Subject: [U-Boot] Disabling video in bootm (cleanup_before_linux) In-Reply-To: References: <505C97FF.7000709@boundarydevices.com> <20120921192204.3b48d3f3@wker> <505CA775.5080308@boundarydevices.com> Message-ID: <505DDACA.7070604@boundarydevices.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 09/22/2012 06:35 AM, Otavio Salvador wrote: > On Fri, Sep 21, 2012 at 2:44 PM, Eric Nelson > wrote: >> On 09/21/2012 10:22 AM, Anatolij Gustschin wrote: >>> >>> Hi Eric, >>> >>> On Fri, 21 Sep 2012 09:38:23 -0700 >>> Eric Nelson wrote: >>> >>>> Hi all, >>>> >>>> While looking into some trouble booting the latest Linux kernel patches >>>> for i.MX6 display support, I found that the kernel driver was thrown off >>>> by >>>> the interrupt status bits in the i.MX6 IPU. >>>> >>>> Until and unless we have the ability to hand off a 'live' display, it >>>> seems >>>> that we should disable the video driver as a part of the 'bootm' process. >>>> >>>> At the very least, doing this will avoid the possibility of trash on the >>>> display during the transition. >>>> >>>> I've been looking, and I don't see a place to tap into this process. >>>> It seems that having a shutdown routine for the display drivers >>>> (cfb_console?) is the way to go. >>> >>> >>> cfb_console driver is a renderer of the characters and bitmaps >>> to the framebuffer memory and is not a good place for a shutdown >>> routine, I think. But we can add a shutdown function to the IPU >>> driver drivers/video/mxc_ipuv3_fb.c and call it before booting. >>> bootm code in common/cmd_bootm.c has a weak arch_preboot_os() >>> function that can be overridden by platform specific preboot >>> routine. We could define a preboot function in >>> >>> arch/arm/cpu/armv7/mx6/soc.c >>> or in >>> arch/arm/cpu/armv7/imx-common/cpu.c >>> >>> and call IPU shutdown routine in it. >>> >> >> Thanks Anatolij. >> >> This is just what we need. I'll send a patch shortly. > > It would be nice to try to add support for mx5 too so we fix same boot > hungs in mx5 kernels. I am adding Fabio in CC as he knows more about > it. > Hi Otavio, I believe it will work on MX5 boards as well, though I haven't tested. http://patchwork.ozlabs.org/patch/185928/ Regards, Eric