This allow us to debug how long take each SMM call and how long is system freezed in SMM handler.
Signed-off-by: Pali Rohár <[email protected]> --- drivers/hwmon/dell-smm-hwmon.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c index 7a2764a..8a66a42 100644 --- a/drivers/hwmon/dell-smm-hwmon.c +++ b/drivers/hwmon/dell-smm-hwmon.c @@ -137,6 +137,14 @@ static int i8k_smm(struct smm_regs *regs) int eax = regs->eax; cpumask_var_t old_mask; +#ifdef DEBUG + int ebx = regs->ebx; + unsigned long duration; + ktime_t calltime, delta, rettime; + + calltime = ktime_get(); +#endif + /* SMM requires CPU 0 */ if (!alloc_cpumask_var(&old_mask, GFP_KERNEL)) return -ENOMEM; @@ -208,6 +216,15 @@ static int i8k_smm(struct smm_regs *regs) out: set_cpus_allowed_ptr(current, old_mask); free_cpumask_var(old_mask); + +#ifdef DEBUG + rettime = ktime_get(); + delta = ktime_sub(rettime, calltime); + duration = ktime_to_ns(delta) >> 10; + pr_debug("smm(0x%.4x 0x%.4x) = 0x%.4x (took %7lu usecs)\n", eax, ebx, + (rc ? 0xffff : regs->eax & 0xffff), duration); +#endif + return rc; } -- 1.7.9.5
