Re: [igt-dev] [PATCH i-g-t 2/2] lib/igt_aux: Enable PM Suspend dbg messages

["Nilawar, Badal" <badal.nilawar@intel.com>]

On 15-06-2023 14:02, Anshuman Gupta wrote:
> Enabling PM Suspend dbg messages by turning on
> /sys/power/pm_debug_messages switch also adding an
> exit handler provision to restore the
> pm_debug_messagesvstate.
> 
> Signed-off-by: Anshuman Gupta <anshuman.gupta@intel.com>
> ---
>   lib/igt_aux.c | 25 +++++++++++++++++++++----
>   1 file changed, 21 insertions(+), 4 deletions(-)
> 
> diff --git a/lib/igt_aux.c b/lib/igt_aux.c
> index 425a1f911..87c3933a5 100644
> --- a/lib/igt_aux.c
> +++ b/lib/igt_aux.c
> @@ -695,6 +695,7 @@ void igt_print_activity(void)
>   
>   static int autoresume_delay;
>   bool __console_suspend_saved_state;
> +bool __pm_debug_messages_state;
>   
>   #define SYSFS_MODULE_PRINTK "/sys/module/printk/parameters/"
>   #define CONSOLE_SUSPEND_DISABLE false
> @@ -905,7 +906,7 @@ static bool is_mem_sleep_state_supported(int power_dir, enum igt_mem_sleep state
>   
>   static void igt_aux_pm_suspend_dbg_restore_exit_handler(int sig)
>   {
> -	int sysfs_fd;
> +	int sysfs_fd, power_dir;
>   
>   	sysfs_fd = open(SYSFS_MODULE_PRINTK, O_RDONLY);
>   
> @@ -913,10 +914,19 @@ static void igt_aux_pm_suspend_dbg_restore_exit_handler(int sig)
>   		return;
>   
>   	igt_sysfs_set_boolean(sysfs_fd, "console_suspend", __console_suspend_saved_state);
Close sysfs_fd here to avoid return without closing it when opening 
power_dir fails.

Regards,
Badal> +	power_dir = open("/sys/power", O_RDONLY);
> +
> +	if (power_dir <  0)
> +		return;
> +
> +	if (!faccessat(power_dir, "pm_debug_messages", R_OK |  W_OK, 0))
> +		igt_sysfs_set_boolean(power_dir, "pm_debug_messages", __pm_debug_messages_state);
> +
>   	close(sysfs_fd);
> +	close(power_dir);
>   }
>   
> -static void igt_aux_enable_pm_suspend_dbg(void)
> +static void igt_aux_enable_pm_suspend_dbg(int power_dir)
>   {
>   	int sysfs_fd;
>   
> @@ -924,11 +934,18 @@ static void igt_aux_enable_pm_suspend_dbg(void)
>   	if (sysfs_fd > 0) {
>   		__console_suspend_saved_state = igt_sysfs_get_boolean(sysfs_fd, "console_suspend");
>   		igt_sysfs_set_boolean(sysfs_fd, "console_suspend", CONSOLE_SUSPEND_DISABLE);
> -		igt_install_exit_handler(igt_aux_pm_suspend_dbg_restore_exit_handler);
>   	} else {
>   		igt_warn("Unable to open printk parameters Err:%d\n", errno);
>   	}
>   
> +	/* pm_debug_messages depends on  CONFIG_PM_SLEEP_DEBUG */
> +	if (!faccessat(power_dir, "pm_debug_messages", R_OK |  W_OK, 0)) {
> +		__pm_debug_messages_state = igt_sysfs_get_boolean(sysfs_fd, "pm_debug_messages");
> +		igt_sysfs_set_boolean(power_dir, "pm_debug_messages", true);
> +	}
> +
> +	igt_install_exit_handler(igt_aux_pm_suspend_dbg_restore_exit_handler);
> +
>   	close(sysfs_fd);
>   }
>   
> @@ -970,7 +987,7 @@ void igt_system_suspend_autoresume(enum igt_suspend_state state,
>   		      "Suspend to disk requires swap space.\n");
>   
>   	orig_test = get_suspend_test(power_dir);
> -	igt_aux_enable_pm_suspend_dbg();
> +	igt_aux_enable_pm_suspend_dbg(power_dir);
>   
>   	if (state == SUSPEND_STATE_S3) {
>   		orig_mem_sleep = get_mem_sleep();