From 73e0e496afdac9a5190eb3b9c51fdfebcc14ebd4 Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Fri, 6 Feb 2015 11:42:43 -0800 Subject: clkdev: Always allocate a struct clk and call __clk_get() w/ CCF of_clk_get_by_clkspec() returns a struct clk pointer but it doesn't create a new handle for the consumers when we're using the common clock framework. Instead it just returns whatever the clk provider hands out. When the consumers go to call clk_put() we get an Oops. Unable to handle kernel paging request at virtual address 00200200 pgd = c0004000 [00200200] *pgd=00000000 Internal error: Oops: 805 [#1] PREEMPT SMP ARM Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.19.0-rc1-00104-ga251361a-dirty #992 Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) task: ee00b000 ti: ee088000 task.ti: ee088000 PC is at __clk_put+0x24/0xd0 LR is at clk_prepare_lock+0xc/0xec pc : [] lr : [] psr: 20000153 sp : ee089de8 ip : 00000000 fp : 00000000 r10: ee02f480 r9 : 00000001 r8 : 00000000 r7 : ee031cc0 r6 : ee089e08 r5 : 00000000 r4 : ee02f480 r3 : 00100100 r2 : 00200200 r1 : 0000091e r0 : 00000001 Flags: nzCv IRQs on FIQs off Mode SVC_32 ISA ARM Segment kernel Control: 10c5387d Table: 4000404a DAC: 00000015 Process swapper/0 (pid: 1, stack limit = 0xee088238) Stack: (0xee089de8 to 0xee08a000) 9de0: ee7c8f14 c03f0ec8 ee089e08 00000000 c0718dc8 00000001 9e00: 00000000 c04ee0f0 ee7e0844 00000001 00000181 c04edb58 ee2bd320 00000000 9e20: 00000000 c011dc5c ee16a1e0 00000000 00000000 c0718dc8 ee16a1e0 ee2bd1e0 9e40: c0641740 ee16a1e0 00000000 ee2bd320 c0718dc8 ee1d3e10 ee1d3e10 00000000 9e60: c0769a88 00000000 c0718dc8 00000000 00000000 c02c3124 c02c310c ee1d3e10 9e80: c07b4eec 00000000 c0769a88 c02c1d0c ee1d3e10 c0769a88 ee1d3e44 00000000 9ea0: c07091dc c02c1eb8 00000000 c0769a88 c02c1e2c c02c0544 ee005478 ee1676c0 9ec0: c0769a88 ee3a4e80 c0760ce8 c02c150c c0669b90 c0769a88 c0746cd8 c0769a88 9ee0: c0746cd8 ee2bc4c0 c0778c00 c02c24e0 00000000 c0746cd8 c0746cd8 c07091f0 9f00: 00000000 c0008944 c04f405c 00000025 ee00b000 60000153 c074ab00 00000000 9f20: 00000000 c074ab90 60000153 00000000 ef7fca5d c050860c 000000b6 c0036b88 9f40: c065ecc4 c06bc728 00000006 00000006 c074ab30 ef7fca40 c0739bdc 00000006 9f60: c0718dbc c0778c00 000000b6 c0718dc8 c06ed598 c06edd64 00000006 00000006 9f80: c06ed598 c003b438 00000000 c04e64f4 00000000 00000000 00000000 00000000 9fa0: 00000000 c04e64fc 00000000 c000e838 00000000 00000000 00000000 00000000 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 c0c0c0c0 c0c0c0c0 [] (__clk_put) from [] (of_clk_set_defaults+0xe0/0x2c0) [] (of_clk_set_defaults) from [] (platform_drv_probe+0x18/0xa4) [] (platform_drv_probe) from [] (driver_probe_device+0x10c/0x22c) [] (driver_probe_device) from [] (__driver_attach+0x8c/0x90) [] (__driver_attach) from [] (bus_for_each_dev+0x54/0x88) [] (bus_for_each_dev) from [] (bus_add_driver+0xd4/0x1d0) [] (bus_add_driver) from [] (driver_register+0x78/0xf4) [] (driver_register) from [] (fimc_md_init+0x14/0x30) [] (fimc_md_init) from [] (do_one_initcall+0x80/0x1d0) [] (do_one_initcall) from [] (kernel_init_freeable+0x108/0x1d4) [] (kernel_init_freeable) from [] (kernel_init+0x8/0xec) [] (kernel_init) from [] (ret_from_fork+0x14/0x3c) Code: ebfff4ae e5943014 e5942018 e3530000 (e5823000) Let's create a per-user handle here so that clk_put() can properly unlink it and free the handle. Now that we allocate a clk structure here we need to free it if __clk_get() fails so bury the __clk_get() call in __of_clk_get_from_provider(). We need to handle the same problem in clk_get_sys() so export __clk_free_clk() to clkdev.c and do the same thing, except let's use a union to make this code #ifdef free. This fixes the above crash, properly calls __clk_get() when of_clk_get_from_provider() is called, and cleans up the clk structure on the error path of clk_get_sys(). Fixes: 035a61c314eb "clk: Make clk API return per-user struct clk instances" Reported-by: Sylwester Nawrocki Reported-by: Alban Browaeys Tested-by: Sylwester Nawrocki Tested-by: Alban Browaeys Reviewed-by: Tomeu Vizoso Signed-off-by: Stephen Boyd Signed-off-by: Michael Turquette --- drivers/clk/clk.h | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) (limited to 'drivers/clk/clk.h') diff --git a/drivers/clk/clk.h b/drivers/clk/clk.h index 23c44e51df69..ba845408cc3e 100644 --- a/drivers/clk/clk.h +++ b/drivers/clk/clk.h @@ -13,10 +13,27 @@ struct clk_hw; #if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK) struct clk *of_clk_get_by_clkspec(struct of_phandle_args *clkspec); -struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec); +struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec, + const char *dev_id, const char *con_id); void of_clk_lock(void); void of_clk_unlock(void); #endif +#ifdef CONFIG_COMMON_CLK struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id, const char *con_id); +void __clk_free_clk(struct clk *clk); +#else +/* All these casts to avoid ifdefs in clkdev... */ +static inline struct clk * +__clk_create_clk(struct clk_hw *hw, const char *dev_id, const char *con_id) +{ + return (struct clk *)hw; +} +static inline void __clk_free_clk(struct clk *clk) { } +static struct clk_hw *__clk_get_hw(struct clk *clk) +{ + return (struct clk_hw *)clk; +} + +#endif -- cgit v1.2.3