From mboxrd@z Thu Jan 1 00:00:00 1970 From: t-kristo@ti.com (Tero Kristo) Date: Thu, 23 Feb 2012 11:00:01 +0200 Subject: [PATCHv2 8/8] arm: omap3: prevent per_clkdm from attempting manual domain transitions In-Reply-To: <87pqd6xzno.fsf@ti.com> References: <1329320274-481-1-git-send-email-t-kristo@ti.com> <1329320274-481-9-git-send-email-t-kristo@ti.com> <87pqdf99c2.fsf@ti.com> <1329382652.4102.386.camel@sokoban> <1329398159.4102.391.camel@sokoban> <1329405804.4102.400.camel@sokoban> <1329410895.4102.404.camel@sokoban> <877gzmit2c.fsf@ti.com> <1329470938.4102.408.camel@sokoban> <87pqd6xzno.fsf@ti.com> Message-ID: <1329987601.4102.494.camel@sokoban> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, 2012-02-22 at 14:37 -0800, Kevin Hilman wrote: > Tero Kristo writes: > > > On Thu, 2012-02-16 at 09:31 -0800, Kevin Hilman wrote: > >> Tero Kristo writes: > >> > >> > On Thu, 2012-02-16 at 21:15 +0530, Shilimkar, Santosh wrote: > >> >> On Thu, Feb 16, 2012 at 8:53 PM, Tero Kristo wrote: > >> >> > On Thu, 2012-02-16 at 15:15 +0200, Tero Kristo wrote: > >> >> >> On Thu, 2012-02-16 at 15:27 +0530, Shilimkar, Santosh wrote: > >> >> >> > On Thu, Feb 16, 2012 at 2:27 PM, Tero Kristo wrote: > >> >> >> > > On Wed, 2012-02-15 at 11:37 -0800, Kevin Hilman wrote: > >> >> >> > >> Tero Kristo writes: > >> >> >> > >> > >> >> >> > >> > Attempting this will cause problems especially with off-mode enabled. > >> >> >> > >> > >> >> >> > >> Please be more verbose about the problems seen, and the root cause(s). > >> >> >> > >> > >> >> >> > > > >> >> >> > > I was actually looking forward for some help with this commit message, > >> >> >> > > as I am still not quite sure what is going on in here. :) Here is the > >> >> >> > > log for suspend (btw, cam_pwrdm does not go to off in mainline yet, but > >> >> >> > > I think that is probably fixed by the patch from Paul, > >> >> >> > > omap_set_pwrdm_state() does not work properly.) The warning comes out > >> >> >> > > after wakeup from off-mode, and it is triggered by the disabling of > >> >> >> > > autodeps before off-mode entry. > >> >> >> > > > >> >> >> > This mostly indicates that one of the per clock-domain module > >> >> >> > clock turning ON seems to be not working well with auto deps > >> >> >> > disabled. This leads to interconnect violation. > >> >> >> > > >> >> >> > if not tried already, can you put the per_clockdomain in SW_WKUP > >> >> >> > in the low power code early resume path and see if this > >> >> >> > error goes away. > >> >> >> > >> >> >> This seems to get rid of the dump also. It looks like some driver resume > >> >> >> is not behaving nicely, I am trying to pinpoint the culprit currently > >> >> >> and see whether it can provide more info. > >> >> > > >> >> > Okay, I have some more info about this now. > >> >> > > >> >> > What happens is that when entering off-mode, PER domain remains OFF even > >> >> > during the execution of the exit phase from omap_sram_idle. Adding a > >> >> > manual SW_WKUP it comes up and there are no issues. If autodeps are > >> >> > enabled on the domain, it comes back from off mode as active. > >> >> > > >> >> > Looking further in the code, we have this at the end of omap_sram_idle: > >> >> > > >> >> > if (per_next_state < PWRDM_POWER_ON) { > >> >> > per_prev_state = pwrdm_read_prev_pwrst(per_pwrdm); > >> >> > omap2_gpio_resume_after_idle(); > >> >> > wake_per(); > >> >> > if (per_prev_state == PWRDM_POWER_OFF) > >> >> > omap3_per_restore_context(); > >> >> > } > >> >> > > >> >> > ... which seems to assume that per domain is on. Gpio code does not > >> >> > control any clocks currently, as it only requires the interface clock to > >> >> > be on, and as this is autoidled.... > >> >> > > >> >> > Any comments how we should handle this? Shall we just keep these two > >> >> > patches for handling this or add some different hackery for the gpio > >> >> > issue? > >> >> > > >> >> Good. I thought too that issue will disappear. > >> >> The issue is pretty clear. Technically every driver pm_runtime() code should > >> >> be able to manage a clock->clockdomain->power domain power up/down > >> >> sequence. That should work without auto deps. > >> >> > >> >> Do you narrowed down which driver resume is creating the dump ? > >> >> UART , GPIO ? > >> > > >> > It is the gpio base stuff called from omap_sram_idle(), basically the > >> > restore context part. If I force enable per domain before the code > >> > snippet before, there is no dump, but if it is done after, I get the > >> > dump. > >> > > >> > The thing is that gpio driver doesn't currently have this kind of > >> > mechanism for the restore context part, at least not on omap3 due to > >> > above clocking issue (only autoidled interface clock is used.) > >> > >> I'm not sure if it fully addresses this, but Tarun's series converts > >> GPIO to runtime PM. > >> > >> Can you try with Tarun's series. See the for_3.4/gpio_cleanup_fixes_v9 > >> branch here: > >> git://gitorious.org/~tarunkanti/omap-sw-develoment/tarunkantis-linux-omap-dev.git > > > > It does something for the issue, but I still get this during suspend to > > off: > > > > [ 11.284973] PM: Syncing filesystems ... done. > > [ 11.379241] Freezing user space processes ... (elapsed 0.02 seconds) > > done. > > [ 11.408233] Freezing remaining freezable tasks ... (elapsed 0.02 > > seconds) don > > e. > > [ 11.439239] Suspending console(s) (use no_console_suspend to debug) > > [ 11.564178] PM: suspend of devices complete after 115.506 msecs > > [ 11.567382] PM: late suspend of devices complete after 3.204 msecs > > [ 11.567443] Disabling non-boot CPUs ... > > [ 12.004089] Powerdomain (cam_pwrdm) didn't enter target state 0 > > [ 12.004119] Could not enter target state in pm_suspend > > [ 12.009368] PM: early resume of devices complete after 4.944 msecs > > [ 12.436645] PM: resume of devices complete after 426.086 msecs > > [ 12.480285] Restarting tasks ... done. > > /sys/kernel/debu[ 12.488433] ------------[ cut here ]------------ > > [ 12.494415] WARNING: at arch/arm/mach-omap2/omap_hwmod.c:1604 _idle > > +0x164/0x1 > > 7c() > > [ 12.502258] omap_hwmod: gpio6: idle state can only be entered from > > enabled st > > ate > > [ 12.509979] Modules linked in: > > [ 12.513214] [] (unwind_backtrace+0x0/0xf4) from > > [] (warn_ > > slowpath_common+0x4c/0x64) > > [ 12.523071] [] (warn_slowpath_common+0x4c/0x64) from > > [] ( > > warn_slowpath_fmt+0x30/0x40) > > [ 12.533081] [] (warn_slowpath_fmt+0x30/0x40) from > > [] (_id > > le+0x164/0x17c) > > [ 12.541931] [] (_idle+0x164/0x17c) from [] > > (omap_hwmod_id > > le+0x28/0x3c) > > [ 12.550567] [] (omap_hwmod_idle+0x28/0x3c) from > > [] (omap_ > > device_idle_hwmods+0x24/0x3c) > > [ 12.560699] [] (omap_device_idle_hwmods+0x24/0x3c) from > > [ > > ] (_omap_device_deactivate+0xa4/0x138) > > [ 12.571594] [] (_omap_device_deactivate+0xa4/0x138) from > > [ >>] (omap_device_idle+0x28/0x54) > > [ 12.581909] [] (omap_device_idle+0x28/0x54) from > > [] (_od_ > > runtime_suspend+0x1c/0x24) > > [ 12.591735] [] (_od_runtime_suspend+0x1c/0x24) from > > [] (_ > > _rpm_callback+0x2c/0x78) > > [ 12.601379] [] (__rpm_callback+0x2c/0x78) from [] > > (rpm_su > > spend+0x264/0x6c4) > > [ 12.610504] [] (rpm_suspend+0x264/0x6c4) from [] > > (__pm_ru > > ntime_suspend+0x5c/0x74) > > [ 12.620178] [] (__pm_runtime_suspend+0x5c/0x74) from > > [] ( > > omap2_gpio_prepare_for_idle+0x50/0x64) > > [ 12.631103] [] (omap2_gpio_prepare_for_idle+0x50/0x64) from > > [ > d30>] (omap_sram_idle+0xa0/0x3b0) > > [ 12.641571] [] (omap_sram_idle+0xa0/0x3b0) from > > [] (omap3 > > _pm_idle+0x60/0x178) > > [ 12.650848] [] (omap3_pm_idle+0x60/0x178) from [] > > (cpu_id > > le+0xc4/0x108) > > [ 12.659606] [] (cpu_idle+0xc4/0x108) from [] > > (start_kerne > > l+0x2b0/0x304) > > [ 12.668365] ---[ end trace 441b8fea2b56dcb1 ]--- > > > > > > Also, this goes away if I manually force wakeup for the per domain, so > > this might be caused by some additional latency. > > > > What platform are you testing on? This is with omap3530 beagle. > When I test Tarun's series with off-mode on 3430/n900 suspend/resume > works fine. But when I add your v2 series, it never comes out of > suspend, and I don't get a kernel dump either. Did you try without Tarun's series and see what happens in that case? > Can you debug this a little further so we can explain what's going on > here? I don't have capability to test with any other omap3 device than beagle, so don't know what I can accomplish here. I just got omap4 cswr working yesterday with mainline, so I can try with that one and see how it behaves (omap4 requires some additional patching for the usecounting though.) -Tero