• Suman Anna's avatar
    ARM: OMAP2+: hwmod: fix _idle() hwmod state sanity check sequence · c20c8f75
    Suman Anna authored
    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)
     [<c0018e60>] (unwind_backtrace) from [<c0014dc4>] (show_stack+0x10/0x14)
     [<c0014dc4>] (show_stack) from [<c037ac28>] (dump_stack+0x90/0xc0)
     [<c037ac28>] (dump_stack) from [<c003f420>] (warn_slowpath_common+0x78/0xb4)
     [<c003f420>] (warn_slowpath_common) from [<c003f48c>] (warn_slowpath_fmt+0x30/0x40)
     [<c003f48c>] (warn_slowpath_fmt) from [<c0028c20>] (_idle+0x1e4/0x240)
     [<c0028c20>] (_idle) from [<c0029080>] (omap_hwmod_idle+0x28/0x48)
     [<c0029080>] (omap_hwmod_idle) from [<c002a5a4>] (omap_device_idle+0x3c/0x90)
     [<c002a5a4>] (omap_device_idle) from [<c0427a90>] (__rpm_callback+0x2c/0x60)
     [<c0427a90>] (__rpm_callback) from [<c0427ae4>] (rpm_callback+0x20/0x80)
     [<c0427ae4>] (rpm_callback) from [<c0427f84>] (rpm_suspend+0x138/0x74c)
     [<c0427f84>] (rpm_suspend) from [<c0428b78>] (__pm_runtime_idle+0x78/0xa8)
     [<c0428b78>] (__pm_runtime_idle) from [<c041f514>] (__device_release_driver+0x64/0x100)
     [<c041f514>] (__device_release_driver) from [<c041f5d0>] (device_release_driver+0x20/0x2c)
     [<c041f5d0>] (device_release_driver) from [<c041d85c>] (unbind_store+0x78/0xf8)
     [<c041d85c>] (unbind_store) from [<c0206df8>] (kernfs_fop_write+0xc0/0x1c4)
     [<c0206df8>] (kernfs_fop_write) from [<c018a120>] (__vfs_write+0x20/0xdc)
     [<c018a120>] (__vfs_write) from [<c018a9cc>] (vfs_write+0x90/0x164)
     [<c018a9cc>] (vfs_write) from [<c018b1f0>] (SyS_write+0x44/0x9c)
     [<c018b1f0>] (SyS_write) from [<c0010420>] (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: 747834ab ("ARM: OMAP2+: hwmod: revise hardreset behavior")
    Signed-off-by: default avatarSuman Anna <s-anna@ti.com>
    Signed-off-by: default avatarPaul Walmsley <paul@pwsan.com>
    c20c8f75
omap_hwmod.c 111 KB