Hi Tomi, On 22.12.2011 14:13, Tomi Valkeinen wrote: > On Thu, 2011-12-22 at 02:00 +0100, Ilya Yanok wrote: >> Resetting DISPC when a DISPC output is enabled causes the DSS to go into >> an inconsistent state. >> >> commit b923d40dd4211c4ef7d4efa2bd81b7ca1d8744c1 >> Author: Archit Taneja <archit@xxxxxx> >> Date: Thu Oct 6 18:04:08 2011 -0600 >> >> ARM: OMAP2PLUS: DSS: Ensure DSS works correctly if display is >> enabled in bootloader >> >> tries to deal with this problem by checking if display is enabled and >> disabling it before doing reset. >> >> But in my setup dss_dispc is resetted from omap_hwmod_setup_all function >> _before_ calling omap_dss_reset. So when dispc_disable_outputs is >> executed dispc is already reset and nothing happens. > > Hmm, why is that? You don't have the dss hwmod before dispc in the list > of hwmods? The code presumes that dss hwmod is handled first. Looking at the arch/arm/mach-omap2/omap_hwmod_3xxx_data.c I can see that dss_dispc is in the list of generic hwmods which is registered first while dss_core hwmod is in revision-specific lists which are registered later. I think this is the real root of the problem, thanks for pointing this out! > >> This patch and HWMOD_INIT_NO_RESET flags to dss_dispc hwmod thus leaving >> DISPC untouched so that omap_dss_reset can take care of it. > > omap_dss_reset() doesn't reset dispc, so this will leave dispc > un-reseted. > > The idea of the current code is to do the reset similarly on all OMAPs. > The sequence should be: > > - omap_dss_reset(), which disables dispc outputs and manually resets dss > registers. > - then the rest of the dss modules reset themselves normally, using the > softreset bit. But currently omap_dss_reset() is called the last. Regards, Ilya. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
