# Wake up from suspend mode on GPIO interrupt **URL:** \ **Category:** Legato Application Framework\ **Created:** [August 16, 2017, 7:04am UTC](https://forum.legato.io/t/wake-up-from-suspend-mode-on-gpio-interrupt/2605 "2017-08-16T07:04:02Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![raf](https://avatars.discourse-cdn.com/v4/letter/r/848f3c/32.png) [@raf](https://forum.legato.io/u/raf)\ **Post date:** [August 16, 2017, 7:04am UTC](https://forum.legato.io/t/wake-up-from-suspend-mode-on-gpio-interrupt/2605/1 "2017-08-16T07:04:02Z")
Hi, I’d like to wake the modem up from suspend mode from a GPIO edge-triggered event. I’m trying to implement a software-driven ‘power button’ to safely shutdown the system when a button is pressed. My current setup is as follows. Module: WP8548 Legato: 16.10.3\_4886ffbf7109055d3448bdff81805ff7\_modified The WP8548 technical specification states that a number of pins can be used to wake the device from USB-SS mode: - GPIO2 - GPIO21 - GPIO36 - GPIO38 - GPIO39 - GPIO42 My application configures GPIO21 as an input with a rising-edge sense using the GPIO API. And this works great provided the system hasn’t already suspended. If I set GPIO21 to a logic 1 while the system is suspended it doesn’t wake up. Here’s the system log retrieved once it resumed from suspend mode (timer-driven) - it appears to be detecting _something_ (wake-n\_gpio77) while suspended but doesn’t wake up. ```auto [49.837692] Suspending console(s) (use no_console_suspend to debug) [49.852189] PM: suspend of devices complete after 6.592 msecs [49.854173] PM: late suspend of devices complete after 1.983 msecs [49.855974] PM: noirq suspend of devices complete after 1.800 msecs [49.856218] msm_pm_enter [49.856218] msm_pm_enter: power collapse [49.856218] msm_mpm_irqs_detectable: cannot monitor 000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000 [49.856218] msm_pm_enter: return [49.857805] PM: noirq resume of devices complete after 1.251 msecs [49.859850] PM: early resume of devices complete after 1.556 msecs [49.863818] PM: resume of devices complete after 3.937 msecs [49.924462] Restarting tasks ... [49.933801] mbim_read: Requests list is empty. Wait. [49.943598] done. [50.002105] mmc0: Re-init card rc = -110 (retries = 5) [50.111002] qup_i2c qup_i2c.0: QUP: I2C status flags :0x1300c8, irq:187 [50.116740] qup_i2c qup_i2c.0: I2C slave addr:0x3a not connected [50.127819] gpio_check_and_wake: wake-n_gpio77 STATE=WAKEUP [50.139996] pm_set_mcu_ulpm_enable: ext pin wu fail 4 [50.159926] gpio_check_and_wake: wake-n_gpio77 STATE=SLEEP [50.167037] gpio_check_and_wake: wake-n_gpio77 STATE=WAKEUP [50.174942] enable_store: invalid input 1 ret -5 [50.179978] pm_set_mcu_ulpm_enable: no wake sources set [50.185411] enable_store: invalid input 1 ret -1 [50.190599] pm_set_mcu_ulpm_enable: no wake sources set [50.195452] enable_store: invalid input 1 ret -1 [50.200549] pm_set_mcu_ulpm_enable: no wake sources set [50.209705] enable_store: invalid input 1 ret -1 [50.217152] pm_set_mcu_ulpm_enable: no wake sources set [50.221516] enable_store: invalid input 1 ret -1 [50.226705] gpio_check_and_wake: wake-n_gpio77 STATE=SLEEP [52.881733] PM: Syncing filesystems ... done. [52.995086] Freezing user space processes ... [53.000488] mbim_read: Waiting failed [53.004120] PM: Wakeup pending, aborting suspend [53.007935] active wakeup source: UNIX [53.011628] active wakeup source: UNIX [53.015687] active wakeup source: UNIX [53.019105] active wakeup source: UNIX [53.022920] active wakeup source: UNIX [53.026552] active wakeup source: UNIX [53.030306] active wakeup source: UNIX [53.034243] active wakeup source: [signalfd] [53.038303] [53.039768] Freezing of tasks aborted after 0.039 seconds (89 tasks refusing to freeze, wq_busy=0): [53.048893] [53.050267] Restarting tasks ... [53.059209] mbim_read: Requests list is empty. Wait. [53.076392] done. [58.038058] gpio_sync_ri: RI owner is Modem [58.041324] gpio_map_name_to_num: gpioRI is not supported [58.958461] msm_serial_hs: Rx break [118.604120] NOHZ: local_softirq_pending 08 [118.684236] NOHZ: local_softirq_pending 08 [127.107034] PM: Syncing filesystems ... done. [127.221303] Freezing user space processes ... [127.227376] mbim_read: Waiting failed [127.231832] (elapsed 0.006 seconds) done. [127.234793] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done. [127.242697] Suspending console(s) (use no_console_suspend to debug) ``` Can the system resume on a GPIO interrupt? ---
**Author:** ![muralinagraj](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@muralinagraj](https://forum.legato.io/u/muralinagraj)\ **Post date:** [February 21, 2018, 7:21am UTC](https://forum.legato.io/t/wake-up-from-suspend-mode-on-gpio-interrupt/2605/2 "2018-02-21T07:21:08Z")
Hi @raf, How you are making the modem to go into suspended mode ? By removing the USB cable connected to the device(modem)? Regards, Muralidhara N.