From 56b7eec01d9aca2f3a4a8697e6f04be67ad1f876 Mon Sep 17 00:00:00 2001 From: Lothar Waßmann Date: Mon, 5 Aug 2013 10:51:14 +0200 Subject: ARM: mxs: Fix BUG() when invoking mxs_restart() from interrupt context MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The mxs_restart() function uses of_iomap() which triggers the following BUG_ON(in_interrupt()) when called in interrupt context (e.g. thru SYSRQ-B): SysRq : Resetting ------------[ cut here ]------------ kernel BUG at mm/vmalloc.c:1310! Internal error: Oops - BUG: 0 [#1] PREEMPT ARM Modules linked in: i2c_dev CPU: 0 PID: 0 Comm: swapper Not tainted 3.11.0-rc2-next-20130729-karo+ #196 task: c04e1c38 ti: c04d8000 task.ti: c04d8000 PC is at __get_vm_area_node.clone.25+0x34/0x140 LR is at get_vm_area_caller+0x38/0x44 pc : [] lr : [] psr: 20000013 sp : c04d9db0 ip : 00000001 fp : 00000001 r10: c8800000 r9 : 00000000 r8 : 000000d0 r7 : 00002000 r6 : 00000001 r5 : 00000001 r4 : 00002000 r3 : 00010000 r2 : 00000001 r1 : c04d9db0 r0 : 00002000 Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel Control: 0005317f Table: 46920000 DAC: 00000017 Process swapper (pid: 0, stack limit = 0xc04d81b8) Create the mapping upon startup from mxs_machine_init(). Signed-off-by: Lothar Waßmann Signed-off-by: Shawn Guo --- arch/arm/mach-mxs/mach-mxs.c | 53 ++++++++++++++++++++++++++------------------ 1 file changed, 32 insertions(+), 21 deletions(-) (limited to 'arch/arm/mach-mxs/mach-mxs.c') diff --git a/arch/arm/mach-mxs/mach-mxs.c b/arch/arm/mach-mxs/mach-mxs.c index 4b210f278d47..b5a2c4a68e34 100644 --- a/arch/arm/mach-mxs/mach-mxs.c +++ b/arch/arm/mach-mxs/mach-mxs.c @@ -62,6 +62,8 @@ static u32 chipid; static u32 socid; +static void __iomem *reset_addr; + static inline void __mxs_setl(u32 mask, void __iomem *reg) { __raw_writel(mask, reg + MXS_SET_ADDR); @@ -400,6 +402,27 @@ static const char __init *mxs_get_revision(void) return kasprintf(GFP_KERNEL, "%s", "Unknown"); } +#define MX23_CLKCTRL_RESET_OFFSET 0x120 +#define MX28_CLKCTRL_RESET_OFFSET 0x1e0 + +static int __init mxs_restart_init(void) +{ + struct device_node *np; + + np = of_find_compatible_node(NULL, NULL, "fsl,clkctrl"); + reset_addr = of_iomap(np, 0); + if (!reset_addr) + return -ENODEV; + + if (of_device_is_compatible(np, "fsl,imx23-clkctrl")) + reset_addr += MX23_CLKCTRL_RESET_OFFSET; + else + reset_addr += MX28_CLKCTRL_RESET_OFFSET; + of_node_put(np); + + return 0; +} + static void __init mxs_machine_init(void) { struct device_node *root; @@ -443,12 +466,12 @@ static void __init mxs_machine_init(void) of_platform_populate(NULL, of_default_bus_match_table, NULL, parent); + mxs_restart_init(); + if (of_machine_is_compatible("karo,tx28")) tx28_post_init(); } -#define MX23_CLKCTRL_RESET_OFFSET 0x120 -#define MX28_CLKCTRL_RESET_OFFSET 0x1e0 #define MXS_CLKCTRL_RESET_CHIP (1 << 1) /* @@ -456,28 +479,16 @@ static void __init mxs_machine_init(void) */ static void mxs_restart(enum reboot_mode mode, const char *cmd) { - struct device_node *np; - void __iomem *reset_addr; + if (reset_addr) { + /* reset the chip */ + __mxs_setl(MXS_CLKCTRL_RESET_CHIP, reset_addr); - np = of_find_compatible_node(NULL, NULL, "fsl,clkctrl"); - reset_addr = of_iomap(np, 0); - if (!reset_addr) - goto soft; + pr_err("Failed to assert the chip reset\n"); - if (of_device_is_compatible(np, "fsl,imx23-clkctrl")) - reset_addr += MX23_CLKCTRL_RESET_OFFSET; - else - reset_addr += MX28_CLKCTRL_RESET_OFFSET; - - /* reset the chip */ - __mxs_setl(MXS_CLKCTRL_RESET_CHIP, reset_addr); - - pr_err("Failed to assert the chip reset\n"); - - /* Delay to allow the serial port to show the message */ - mdelay(50); + /* Delay to allow the serial port to show the message */ + mdelay(50); + } -soft: /* We'll take a jump through zero as a poor second */ soft_restart(0); } -- cgit