The hwmod init sequence involves initializing and idling all the hwmods during bootup. If a module class has sysconfig, the init sequence utilizes the module register base for performing any sysc configuration. The module address space is being removed from hwmod database and retrieved from the <reg> property of the corresponding DT node. If a hwmod does not have its corresponding DT node defined and the memory address space is not defined in the corresponding omap_hwmod_ocp_if, then the module register target address space would be NULL and any sysc programming would result in a NULL pointer dereference and a kernel boot hang. Handle this scenario by checking for a valid module address space during the _init of each hwmod, and leaving it in the registered state if no module register address base is defined in either of the hwmod data or the DT data. Signed-off-by: Suman Anna <s-anna@xxxxxx> --- This patch helps break the dependencies between hwmod entries and corresponding DT entries (especially on OMAP5, where most of the address spaces are already cleaned up and the current data files have minimal entries) and fixes any boot issues due to missing addresses. See for reference, http://marc.info/?t=138005421400003&r=1&w=2 Tested on BeagleXM, Panda4, BeagleBone Black and Panda5 using Tero's v7 clk DT patches and Benoit's for-3.13/dts on top of 3.12-rc3 arch/arm/mach-omap2/omap_hwmod.c | 29 +++++++++++++++++++---------- 1 file changed, 19 insertions(+), 10 deletions(-) diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c index d9ee0ff..1d9edb3 100644 --- a/arch/arm/mach-omap2/omap_hwmod.c +++ b/arch/arm/mach-omap2/omap_hwmod.c @@ -2361,21 +2361,23 @@ static struct device_node *of_dev_hwmod_lookup(struct device_node *np, * Cache the virtual address used by the MPU to access this IP block's * registers. This address is needed early so the OCP registers that * are part of the device's address space can be ioremapped properly. - * No return value. + * + * Returns 0 on success, -EINVAL if an invalid hwmod is passed, and + * -ENOMEM on absent or invalid register target address space. */ -static void __init _init_mpu_rt_base(struct omap_hwmod *oh, void *data) +static int __init _init_mpu_rt_base(struct omap_hwmod *oh, void *data) { struct omap_hwmod_addr_space *mem; void __iomem *va_start = NULL; struct device_node *np; if (!oh) - return; + return -EINVAL; _save_mpu_port_index(oh); if (oh->_int_flags & _HWMOD_NO_MPU_PORT) - return; + return -ENOMEM; mem = _find_mpu_rt_addr_space(oh); if (!mem) { @@ -2384,7 +2386,7 @@ static void __init _init_mpu_rt_base(struct omap_hwmod *oh, void *data) /* Extract the IO space from device tree blob */ if (!of_have_populated_dt()) - return; + return -ENOMEM; np = of_dev_hwmod_lookup(of_find_node_by_name(NULL, "ocp"), oh); if (np) @@ -2395,13 +2397,14 @@ static void __init _init_mpu_rt_base(struct omap_hwmod *oh, void *data) if (!va_start) { pr_err("omap_hwmod: %s: Could not ioremap\n", oh->name); - return; + return -ENOMEM; } pr_debug("omap_hwmod: %s: MPU register target at va %p\n", oh->name, va_start); oh->_mpu_rt_va = va_start; + return 0; } /** @@ -2414,8 +2417,8 @@ static void __init _init_mpu_rt_base(struct omap_hwmod *oh, void *data) * registered at this point. This is the first of two phases for * hwmod initialization. Code called here does not touch any hardware * registers, it simply prepares internal data structures. Returns 0 - * upon success or if the hwmod isn't registered, or -EINVAL upon - * failure. + * upon success or if the hwmod isn't registered or if the hwmod's + * address space is not defined, or -EINVAL upon failure. */ static int __init _init(struct omap_hwmod *oh, void *data) { @@ -2424,8 +2427,14 @@ static int __init _init(struct omap_hwmod *oh, void *data) if (oh->_state != _HWMOD_STATE_REGISTERED) return 0; - if (oh->class->sysc) - _init_mpu_rt_base(oh, NULL); + if (oh->class->sysc) { + r = _init_mpu_rt_base(oh, NULL); + if (r < 0) { + WARN(1, "omap_hwmod: %s: doesn't have mpu register target base\n", + oh->name); + return 0; + } + } r = _init_clocks(oh, NULL); if (r < 0) { -- 1.8.4 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
