From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965115AbcHNLOT (ORCPT ); Sun, 14 Aug 2016 07:14:19 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:51945 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933447AbcHNLBZ (ORCPT ); Sun, 14 Aug 2016 07:01:25 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Paul Walmsley" , "Suman Anna" Date: Sat, 13 Aug 2016 18:42:51 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 013/305] ARM: OMAP2+: hwmod: fix _idle() hwmod state sanity check sequence In-Reply-To: X-SA-Exim-Connect-IP: 92.40.249.202 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.37-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Suman Anna commit c20c8f750d9f8f8617f07ee2352d3ff560e66bc2 upstream. The omap_hwmod _enable() function can return success without setting the hwmod state to _HWMOD_STATE_ENABLED for IPs with reset lines when all of the reset lines are asserted. The omap_hwmod _idle() function also performs a similar check, but after checking for the hwmod state first. This triggers the WARN when pm_runtime_get and pm_runtime_put are invoked on IPs with all reset lines asserted. Reverse the checks for hwmod state and reset lines status to fix this. Issue found during a unbind operation on a device with reset lines still asserted, example backtrace below ------------[ cut here ]------------ WARNING: CPU: 1 PID: 879 at arch/arm/mach-omap2/omap_hwmod.c:2207 _idle+0x1e4/0x240() omap_hwmod: mmu_dsp: idle state can only be entered from enabled state Modules linked in: CPU: 1 PID: 879 Comm: sh Not tainted 4.4.0-00008-ga989d951331a #3 Hardware name: Generic OMAP5 (Flattened Device Tree) [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [] (show_stack) from [] (dump_stack+0x90/0xc0) [] (dump_stack) from [] (warn_slowpath_common+0x78/0xb4) [] (warn_slowpath_common) from [] (warn_slowpath_fmt+0x30/0x40) [] (warn_slowpath_fmt) from [] (_idle+0x1e4/0x240) [] (_idle) from [] (omap_hwmod_idle+0x28/0x48) [] (omap_hwmod_idle) from [] (omap_device_idle+0x3c/0x90) [] (omap_device_idle) from [] (__rpm_callback+0x2c/0x60) [] (__rpm_callback) from [] (rpm_callback+0x20/0x80) [] (rpm_callback) from [] (rpm_suspend+0x138/0x74c) [] (rpm_suspend) from [] (__pm_runtime_idle+0x78/0xa8) [] (__pm_runtime_idle) from [] (__device_release_driver+0x64/0x100) [] (__device_release_driver) from [] (device_release_driver+0x20/0x2c) [] (device_release_driver) from [] (unbind_store+0x78/0xf8) [] (unbind_store) from [] (kernfs_fop_write+0xc0/0x1c4) [] (kernfs_fop_write) from [] (__vfs_write+0x20/0xdc) [] (__vfs_write) from [] (vfs_write+0x90/0x164) [] (vfs_write) from [] (SyS_write+0x44/0x9c) [] (SyS_write) from [] (ret_fast_syscall+0x0/0x1c) ---[ end trace a4182013c75a9f50 ]--- While at this, fix the sequence in _shutdown() as well, though there is no easy reproducible scenario. Fixes: 747834ab8347 ("ARM: OMAP2+: hwmod: revise hardreset behavior") Signed-off-by: Suman Anna Signed-off-by: Paul Walmsley Signed-off-by: Ben Hutchings --- arch/arm/mach-omap2/omap_hwmod.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) --- a/arch/arm/mach-omap2/omap_hwmod.c +++ b/arch/arm/mach-omap2/omap_hwmod.c @@ -2263,15 +2263,15 @@ static int _idle(struct omap_hwmod *oh) { pr_debug("omap_hwmod: %s: idling\n", oh->name); + if (_are_all_hardreset_lines_asserted(oh)) + return 0; + if (oh->_state != _HWMOD_STATE_ENABLED) { WARN(1, "omap_hwmod: %s: idle state can only be entered from enabled state\n", oh->name); return -EINVAL; } - if (_are_all_hardreset_lines_asserted(oh)) - return 0; - if (oh->class->sysc) _idle_sysc(oh); _del_initiator_dep(oh, mpu_oh); @@ -2318,6 +2318,9 @@ static int _shutdown(struct omap_hwmod * int ret, i; u8 prev_state; + if (_are_all_hardreset_lines_asserted(oh)) + return 0; + if (oh->_state != _HWMOD_STATE_IDLE && oh->_state != _HWMOD_STATE_ENABLED) { WARN(1, "omap_hwmod: %s: disabled state can only be entered from idle, or enabled state\n", @@ -2325,9 +2328,6 @@ static int _shutdown(struct omap_hwmod * return -EINVAL; } - if (_are_all_hardreset_lines_asserted(oh)) - return 0; - pr_debug("omap_hwmod: %s: disabling\n", oh->name); if (oh->class->pre_shutdown) {