From mboxrd@z Thu Jan 1 00:00:00 1970 From: tony@atomide.com (Tony Lindgren) Date: Mon, 2 Feb 2015 11:21:17 -0800 Subject: [PATCH v13 4/6] clk: Add rate constraints to clocks In-Reply-To: <20150202174646.421.52331@quantum> References: <1422011024-32283-1-git-send-email-tomeu.vizoso@collabora.com> <1422011024-32283-5-git-send-email-tomeu.vizoso@collabora.com> <54CA8662.7040008@codeaurora.org> <20150131013158.GA4323@codeaurora.org> <20150201221856.421.6151@quantum> <20150202161237.GG16250@atomide.com> <20150202174646.421.52331@quantum> Message-ID: <20150202192116.GF9418@atomide.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org * Mike Turquette [150202 09:50]: > Quoting Tony Lindgren (2015-02-02 08:12:37) > > > > [ 10.568206] ------------[ cut here ]------------ > > [ 10.568206] WARNING: CPU: 0 PID: 1 at drivers/clk/clk.c:925 clk_disable+0x28/0x34() > > [ 10.568237] Modules linked in: > > [ 10.568237] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 3.19.0-rc6-next-20150202 #2037 > > [ 10.568237] Hardware name: Generic OMAP4 (Flattened Device Tree) > > [ 10.568267] [] (unwind_backtrace) from [] (show_stack+0x10/0x14) > > [ 10.568267] [] (show_stack) from [] (dump_stack+0x84/0x9c) > > [ 10.568267] [] (dump_stack) from [] (warn_slowpath_common+0x7c/0xb8) > > [ 10.568298] [] (warn_slowpath_common) from [] (warn_slowpath_null+0x1c/0x24) > > [ 10.568298] [] (warn_slowpath_null) from [] (clk_disable+0x28/0x34) > > [ 10.568328] [] (clk_disable) from [] (_disable_clocks+0x18/0x68) > > [ 10.568328] [] (_disable_clocks) from [] (_idle+0x10c/0x214) > > [ 10.568328] [] (_idle) from [] (_setup+0x338/0x410) > > [ 10.568359] [] (_setup) from [] (omap_hwmod_for_each+0x34/0x60) > > [ 10.568359] [] (omap_hwmod_for_each) from [] (__omap_hwmod_setup_all+0x30/0x40) > > [ 10.568389] [] (__omap_hwmod_setup_all) from [] (do_one_initcall+0x80/0x1dc) > > [ 10.568389] [] (do_one_initcall) from [] (kernel_init_freeable+0x204/0x2d0) > > [ 10.568420] [] (kernel_init_freeable) from [] (kernel_init+0x8/0xec) > > [ 10.568420] [] (kernel_init) from [] (ret_from_fork+0x14/0x24) > > [ 10.568420] ---[ end trace cb88537fdc8fa211 ]--- For reference, the above is line 992 in clk-next. > This looks like mis-matched enable/disable calls. We now have unique > struct clk pointers for every call to clk_get. I haven't yet looked > through the hwmod code but I have a feeling that we're doing something > like this: > > /* enable clock */ > my_clk = clk_get(...); > clk_prepare_enable(my_clk); > clk_put(my_clk); > > /* do some work */ > do_work(); > > /* disable clock */ > my_clk = clk_get(...); > clk_disable_unprepare(my_clk); > clk_put(my_clk); > > The above pattern no longer works since my_clk will be two different > unique pointers, but it really should be one stable pointer across the > whole usage of the clk. E.g: > > /* enable clock */ > my_clk = clk_get(...); > clk_prepare_enable(my_clk); > > /* do some work */ > do_work(); > > /* disable clock */ > clk_disable_unprepare(my_clk); > clk_put(my_clk); > > Again, I haven't looked through the code, so the above is just an > educated guess. > > Anyways I am testing with an OMAP4460 Panda ES and I didn't see the > above. Is there a test you are running to get this? Just booting 4430-sdp with omap2plus_defconfig. And git bisect points to 59cf3fcf9baf ("clk: Make clk API return per-user struct clk instances") as you already guessed. > > [ 10.568450] ------------[ cut here ]------------ > > [ 10.568450] WARNING: CPU: 0 PID: 1 at arch/arm/mach-omap2/dpll3xxx.c:436 omap3_noncore_dpll_enable+0xdc/0 > > x10c() > > [ 10.568450] Modules linked in: > > [ 10.568481] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 3.19.0-rc6-next-20150202 #2037 > > [ 10.568481] Hardware name: Generic OMAP4 (Flattened Device Tree) > > [ 10.568481] [] (unwind_backtrace) from [] (show_stack+0x10/0x14) > > [ 10.568511] [] (show_stack) from [] (dump_stack+0x84/0x9c) > > [ 10.568511] [] (dump_stack) from [] (warn_slowpath_common+0x7c/0xb8) > > [ 10.568511] [] (warn_slowpath_common) from [] (warn_slowpath_null+0x1c/0x24) > > [ 10.568542] [] (warn_slowpath_null) from [] (omap3_noncore_dpll_enable+0xdc/0x10c) > > [ 10.568542] [] (omap3_noncore_dpll_enable) from [] (clk_core_enable+0x60/0x9c) > > [ 10.568572] [] (clk_core_enable) from [] (clk_core_enable+0x40/0x9c) > > [ 10.568572] ---[ end trace cb88537fdc8fa212 ]--- > > ... > > This is the same issue discussed already in this thread[0]. Feedback > from Tero & Paul on how to handle it would be nice. Yes that one is a separate issue. > Please let me know if anything else breaks for you. Also off-idle on omap3 seems to be broken by commit 59cf3fcf9baf. Regards, Tony