On 10/29/2013 01:51 PM, Sylwester Nawrocki wrote: > clk_unregister() is currently not implemented and it is required when > a clock provider module needs to be unloaded. > > Normally the clock supplier module is prevented to be unloaded by > taking reference on the module in clk_get(). > > For cases when the clock supplier module deinitializes despite the > consumers of its clocks holding a reference on the module, e.g. when > the driver is unbound through "unbind" sysfs attribute, there are > empty clock ops added. These ops are assigned temporarily to struct > clk and used until all consumers release the clock, to avoid invoking > callbacks from the module which just got removed. This patch is now in Mike's clk-next and hence next-20131031, and causes both a WARN and an OOPS when booting the Tegra Dalmore board. (See log below) If I do the following to fix some other issues: 1) Apply: http://www.spinics.net/lists/arm-kernel/msg283619.html clk: fix boot panic with non-dev-associated clocks 2) Merge some Tegra-specific bug-fixes: https://lkml.org/lkml/2013/10/29/771 Re: pull request for Tegra clock rework and Tegra124 clock support ... then revert this patch a336ed7 "clk: Implement clk_unregister()", everything works again. > [ 0.000000] ------------[ cut here ]------------ > [ 0.000000] WARNING: CPU: 0 PID: 0 at include/linux/kref.h:47 __clk_get+0x6c/0x84() > [ 0.000000] Modules linked in: > [ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.12.0-rc3-00069-g850d089 #172 > [ 0.000000] [<c00158f0>] (unwind_backtrace+0x0/0xf8) from [<c00117a8>] (show_stack+0x10/0x14) > [ 0.000000] [<c00117a8>] (show_stack+0x10/0x14) from [<c053b0b4>] (dump_stack+0x80/0xc4) > [ 0.000000] [<c053b0b4>] (dump_stack+0x80/0xc4) from [<c00251f4>] (warn_slowpath_common+0x64/0x88) > [ 0.000000] [<c00251f4>] (warn_slowpath_common+0x64/0x88) from [<c0025234>] (warn_slowpath_null+0x1c/0x24) > [ 0.000000] [<c0025234>] (warn_slowpath_null+0x1c/0x24) from [<c03a3f98>] (__clk_get+0x6c/0x84) > [ 0.000000] [<c03a3f98>] (__clk_get+0x6c/0x84) from [<c03a17e0>] (of_clk_get+0x5c/0x74) > [ 0.000000] [<c03a17e0>] (of_clk_get+0x5c/0x74) from [<c03a1830>] (of_clk_get_by_name+0x38/0xb4) > [ 0.000000] [<c03a1830>] (of_clk_get_by_name+0x38/0xb4) from [<c073e114>] (tegra_pmc_init+0x70/0x298) > [ 0.000000] [<c073e114>] (tegra_pmc_init+0x70/0x298) from [<c073de68>] (tegra_dt_init_irq+0x10/0x20) > [ 0.000000] [<c073de68>] (tegra_dt_init_irq+0x10/0x20) from [<c0739384>] (init_IRQ+0x24/0x2c) > [ 0.000000] [<c0739384>] (init_IRQ+0x24/0x2c) from [<c0737910>] (start_kernel+0x1a0/0x30c) > [ 0.000000] [<c0737910>] (start_kernel+0x1a0/0x30c) from [<80008074>] (0x80008074) > [ 0.000000] ---[ end trace 1b75b31a2719ed1c ]--- ... > [ 14.674455] Unable to handle kernel paging request at virtual address 6b6b6cc3 > [ 14.681719] pgd = c0004000 > [ 14.684517] [6b6b6cc3] *pgd=00000000 > [ 14.688166] Internal error: Oops: 5 [#1] PREEMPT SMP ARM > [ 14.693507] Modules linked in: > [ 14.696640] CPU: 1 PID: 1 Comm: swapper/0 Tainted: G W 3.12.0-rc3-00069-g850d089 #172 > [ 14.705385] task: ee07ea40 ti: ee098000 task.ti: ee098000 > [ 14.710837] PC is at module_put+0x28/0x78 > [ 14.714916] LR is at tegra_ehci_probe+0xac/0x3b8 > [ 14.719575] pc : [<c0077b18>] lr : [<c031d910>] psr: 20000113 > [ 14.719575] sp : ee099e60 ip : ee018740 fp : 00000000 > [ 14.731092] r10: fffffdfb r9 : ee098000 r8 : fffffdfb > [ 14.736350] r7 : c058ad18 r6 : ee112410 r5 : ee0186c0 r4 : ee098000 > [ 14.742909] r3 : 00000001 r2 : 00000001 r1 : 000004d0 r0 : 6b6b6b6b > [ 14.749473] Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel > [ 14.756824] Control: 10c5387d Table: 8000406a DAC: 00000015 > [ 14.762601] Process swapper/0 (pid: 1, stack limit = 0xee098240) > [ 14.768640] Stack: (0xee099e60 to 0xee09a000) > [ 14.773045] 9e60: ee365800 c031d910 c031d864 c0808e58 ee112410 00000000 c079e924 c074fe3c > [ 14.781273] 9e80: c07374e0 c02a225c c02a2244 c02a1108 00000000 ee112410 c079e924 ee112444 > [ 14.789498] 9ea0: 00000000 c02a12b0 00000000 c079e924 c02a1224 c029f73c ee0880e0 ee1135f4 > [ 14.797722] 9ec0: c079e924 ee37fb40 c0798bd0 c02a07dc c06a645c c079e924 c079e924 00000006 > [ 14.805946] 9ee0: c0760ab8 c07c0900 c074fe3c c02a18c8 c02a2284 c076d118 00000006 c00089d8 > [ 14.814170] 9f00: c07e60d8 ee133840 c0543d24 000000bf c07c0900 00000001 00000000 c0781dd8 > [ 14.822393] 9f20: 60000113 00000001 00000008 c182b1d2 c055e284 c003d620 ee099f64 c004741c > [ 14.830617] 9f40: c06abae4 c070618c 00000006 00000006 c0781dc8 c076d118 00000006 c0760ab8 > [ 14.838841] 9f60: c07c0900 000000b9 c0760ac4 c07374e0 00000000 c0737b78 00000006 00000006 > [ 14.847064] 9f80: c07374e0 ffffffff 00000000 c0536aec 00000000 00000000 00000000 00000000 > [ 14.855288] 9fa0: 00000000 c0536af4 00000000 c000e678 00000000 00000000 00000000 00000000 > [ 14.863509] 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 > [ 14.871732] 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 ffffffff ffffffff > [ 14.879994] [<c0077b18>] (module_put+0x28/0x78) from [<c031d910>] (tegra_ehci_probe+0xac/0x3b8) > [ 14.888782] [<c031d910>] (tegra_ehci_probe+0xac/0x3b8) from [<c02a225c>] (platform_drv_probe+0x18/0x1c) > [ 14.898247] [<c02a225c>] (platform_drv_probe+0x18/0x1c) from [<c02a1108>] (driver_probe_device+0x108/0x224) > [ 14.908050] [<c02a1108>] (driver_probe_device+0x108/0x224) from [<c02a12b0>] (__driver_attach+0x8c/0x90) > [ 14.917607] [<c02a12b0>] (__driver_attach+0x8c/0x90) from [<c029f73c>] (bus_for_each_dev+0x54/0x88) > [ 14.926729] [<c029f73c>] (bus_for_each_dev+0x54/0x88) from [<c02a07dc>] (bus_add_driver+0xd4/0x258) > [ 14.935837] [<c02a07dc>] (bus_add_driver+0xd4/0x258) from [<c02a18c8>] (driver_register+0x78/0xf4) > [ 14.944862] [<c02a18c8>] (driver_register+0x78/0xf4) from [<c00089d8>] (do_one_initcall+0xe4/0x140) > [ 14.953982] [<c00089d8>] (do_one_initcall+0xe4/0x140) from [<c0737b78>] (kernel_init_freeable+0xfc/0x1c4) > [ 14.963624] [<c0737b78>] (kernel_init_freeable+0xfc/0x1c4) from [<c0536af4>] (kernel_init+0x8/0xe4) > [ 14.972748] [<c0536af4>] (kernel_init+0x8/0xe4) from [<c000e678>] (ret_from_fork+0x14/0x3c) > [ 14.981155] Code: e5943004 e2833001 e5843004 f57ff05a (e5903158) > [ 14.987438] ---[ end trace 1b75b31a2719ed1d ]--- > [ 14.992109] note: swapper/0[1] exited with preempt_count 1 > [ 14.997752] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b > [ 14.997752] > [ 15.006970] CPU2: stopping > [ 15.009756] CPU: 2 PID: 0 Comm: swapper/2 Tainted: G D W 3.12.0-rc3-00069-g850d089 #172 > [ 15.018572] [<c00158f0>] (unwind_backtrace+0x0/0xf8) from [<c00117a8>] (show_stack+0x10/0x14) > [ 15.027180] [<c00117a8>] (show_stack+0x10/0x14) from [<c053b0b4>] (dump_stack+0x80/0xc4) > [ 15.035341] [<c053b0b4>] (dump_stack+0x80/0xc4) from [<c00142e8>] (handle_IPI+0xfc/0x120) > [ 15.043587] [<c00142e8>] (handle_IPI+0xfc/0x120) from [<c0008704>] (gic_handle_irq+0x54/0x5c) > [ 15.052183] [<c0008704>] (gic_handle_irq+0x54/0x5c) from [<c00122a0>] (__irq_svc+0x40/0x70) > [ 15.060573] Exception stack(0xee0b7fa0 to 0xee0b7fe8) > [ 15.065671] 7fa0: ffffffed 010d0000 c077b968 00000000 ee0b6000 c07c0747 00000001 c07c0747 > [ 15.073900] 7fc0: c077a44c c077a3d4 c05430cc 00000000 00000001 ee0b7fe8 c000f1dc c000f1d4 > [ 15.082114] 7fe0: 60000113 ffffffff > [ 15.085679] [<c00122a0>] (__irq_svc+0x40/0x70) from [<c000f1d4>] (arch_cpu_idle+0x28/0x38) > [ 15.094019] [<c000f1d4>] (arch_cpu_idle+0x28/0x38) from [<c0061d58>] (cpu_startup_entry+0x60/0x134) > [ 15.103127] [<c0061d58>] (cpu_startup_entry+0x60/0x134) from [<800087a4>] (0x800087a4) > [ 15.111089] CPU3: stopping > [ 15.113872] CPU: 3 PID: 0 Comm: swapper/3 Tainted: G D W 3.12.0-rc3-00069-g850d089 #172 > [ 15.122680] [<c00158f0>] (unwind_backtrace+0x0/0xf8) from [<c00117a8>] (show_stack+0x10/0x14) > [ 15.131284] [<c00117a8>] (show_stack+0x10/0x14) from [<c053b0b4>] (dump_stack+0x80/0xc4) > [ 15.139441] [<c053b0b4>] (dump_stack+0x80/0xc4) from [<c00142e8>] (handle_IPI+0xfc/0x120) > [ 15.147683] [<c00142e8>] (handle_IPI+0xfc/0x120) from [<c0008704>] (gic_handle_irq+0x54/0x5c) > [ 15.156280] [<c0008704>] (gic_handle_irq+0x54/0x5c) from [<c00122a0>] (__irq_svc+0x40/0x70) > [ 15.164669] Exception stack(0xee0b9fa0 to 0xee0b9fe8) > [ 15.169768] 9fa0: ffffffed 010d8000 c077b968 00000000 ee0b8000 c07c0747 00000001 c07c0747 > [ 15.177994] 9fc0: c077a44c c077a3d4 c05430cc 00000000 00000001 ee0b9fe8 c000f1dc c000f1d4 > [ 15.186208] 9fe0: 60000113 ffffffff > [ 15.189771] [<c00122a0>] (__irq_svc+0x40/0x70) from [<c000f1d4>] (arch_cpu_idle+0x28/0x38) > [ 15.198108] [<c000f1d4>] (arch_cpu_idle+0x28/0x38) from [<c0061d58>] (cpu_startup_entry+0x60/0x134) > [ 15.207215] [<c0061d58>] (cpu_startup_entry+0x60/0x134) from [<800087a4>] (0x800087a4) > [ 15.215178] CPU0: stopping > [ 15.217953] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G D W 3.12.0-rc3-00069-g850d089 #172 > [ 15.226758] [<c00158f0>] (unwind_backtrace+0x0/0xf8) from [<c00117a8>] (show_stack+0x10/0x14) > [ 15.235363] [<c00117a8>] (show_stack+0x10/0x14) from [<c053b0b4>] (dump_stack+0x80/0xc4) > [ 15.243522] [<c053b0b4>] (dump_stack+0x80/0xc4) from [<c00142e8>] (handle_IPI+0xfc/0x120) > [ 15.251765] [<c00142e8>] (handle_IPI+0xfc/0x120) from [<c0008704>] (gic_handle_irq+0x54/0x5c) > [ 15.260363] [<c0008704>] (gic_handle_irq+0x54/0x5c) from [<c00122a0>] (__irq_svc+0x40/0x70) > [ 15.268754] Exception stack(0xc0773f68 to 0xc0773fb0) > [ 15.273851] 3f60: ffffffed 010c0000 c077b968 00000000 c0772000 c07c0747 > [ 15.282080] 3f80: 00000001 c07c0747 c077a44c c077a3d4 c05430cc 00000000 00000020 c0773fb0 > [ 15.290297] 3fa0: c000f1dc c000f1d4 60000113 ffffffff > [ 15.295421] [<c00122a0>] (__irq_svc+0x40/0x70) from [<c000f1d4>] (arch_cpu_idle+0x28/0x38) > [ 15.303757] [<c000f1d4>] (arch_cpu_idle+0x28/0x38) from [<c0061d58>] (cpu_startup_entry+0x60/0x134) > [ 15.312874] [<c0061d58>] (cpu_startup_entry+0x60/0x134) from [<c0737a28>] (start_kernel+0x2b8/0x30c) > [ 15.322069] [<c0737a28>] (start_kernel+0x2b8/0x30c) from [<80008074>] (0x80008074)