From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dirk Behme Date: Sun, 23 Sep 2012 18:32:58 +0200 Subject: [U-Boot] [PATCH 1/2] i.MX: mxc_ipuv3_fb: add ipuv3_fb_shutdown() routine to stop IPU before bootm In-Reply-To: <505F313A.1080705@denx.de> References: <20120921192204.3b48d3f3@wker> <1348259795-9314-1-git-send-email-eric.nelson@boundarydevices.com> <1348259795-9314-2-git-send-email-eric.nelson@boundarydevices.com> <505F313A.1080705@denx.de> Message-ID: <505F39BA.90500@gmail.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 23.09.2012 17:56, Stefano Babic wrote: > On 22/09/2012 16:37, Fabio Estevam wrote: >> On Sat, Sep 22, 2012 at 10:42 AM, Otavio Salvador >> wrote: >>> Hello Eric, >>> >>> On Fri, Sep 21, 2012 at 5:36 PM, Eric Nelson >>> wrote: >>>> Signed-off-by: Eric Nelson >>> >>> Did you test it in mx5 too? We seem to need to handle it in mx5 too as >>> we had hungs in FSL kernel when using framebuffer in U-Boot. We're >>> using a patch in kernel for workaround it but it seems your fix does >>> what is need. >> >> I have just tested Eric's series on a mx53loco and it does fix the >> kernel hang issue. >> >> I made some comments on this series and hopefully Eric's v2 can get >> into 2012.10, since this is a bug fix. > > Ok, I am waiting for V2 and I will push it. > > Anyway, a question about the issue. It seems to me that it is not > possible with IPUV3 (I have not tested myself, so my question) to get > the u-boot splashscreen displayed on the LCD until the kernel has > finished to boot. This could be possible (and it is possible on other > SOC) if the IPU is loaded as module instead of statically linked to the > kernel, and if the kernel does not touch the IPU setup. This means also > that it should not disable the clocks used by U-Boot for the IPU. > > But I understand from your patch that this way is not possible on > iMX53/MX6, and IPU must be always disabled. Is this correct ? I'm no expert on this, so I might be wrong and people will correct me: No, not always. It's my understanding that at the *moment* we have to disable the IPU in U-Boot before jumping into the kernel due to a bug in Sascha's kernel IPU driver: http://lists.infradead.org/pipermail/linux-arm-kernel/2012-September/121980.html http://lists.infradead.org/pipermail/linux-arm-kernel/2012-September/122100.html So from my understanding, this isn't a SOC limitation. But we have to do it as long as the kernel's IPU driver isn't fixed. Sorry if this is wrong ;) Best regards Dirk