# USB flash not detected in /dev/ **URL:** \ **Category:** Legato Linux distribution (Yocto project)\ **Created:** [August 23, 2019, 2:12pm UTC](https://forum.legato.io/t/usb-flash-not-detected-in-dev/4644 "2019-08-23T14:12:18Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![MilanVidic](https://avatars.discourse-cdn.com/v4/letter/m/e480ec/32.png) [@MilanVidic](https://forum.legato.io/u/MilanVidic)\ **Post date:** [August 23, 2019, 2:12pm UTC](https://forum.legato.io/t/usb-flash-not-detected-in-dev/4644/1 "2019-08-23T14:12:18Z")
I am using custom board with wp7607 module. When I type > `swiflash -m wp76xx -r` and plug USB flash into board, after board reboots, USB flash doesn’t show in _ **/dev/** _ folder. It will get recognized as **/dev/sda1** only after I unplug the board from power supply and than plug it back on. Simply typing `reboot` doesn’t solve the problem. What is the difference between these two types of restarts? Is there something I can do so USB flash gets recognized with reboot command? **dmesg** output: ``` [19.398984] USB QCMAP NL IOCTL Snd GETNEIGH Succ [19.415355] QCMAP:Start Main [19.453920] USB QCMAP NL IOCTL Snd GETNEIGH Succ [19.545707] QCMAP:Start DHCP server [19.557725] QCMAP:DHCP server started [19.806623] QCMAP:Init Complete [19.851113] USB QCMAP NL IOCTL Snd GETNEIGH Succ [23.397277] sps:BAM 0x04044000 is registered. [23.397544] sps:BAM 0x04044000 (va:0xd1820000) enabled: ver:0x27, number of pipes:6 [24.181201] PSM: DMS Ind register - result: 0, error: 0 [24.181909] PSM: Oprt mode event report req qmi response - result: 0, error: 0 [24.182532] PSM: result - 0 error - 0 [24.182584] PSM: Modem oprt mode - 0 [24.183799] PSM: backup_nv_path /data/psm/psm_nv_backup.txt [24.187264] PSM: Supported: 0 [24.187334] PSM: Log and QMI Init completed [24.187374] PSM: Supported: 0 [24.187623] PSM: Core server init completed [24.187964] PSM: Client and event thread created [24.827999] gpio_check_and_wake: wake-n_gpio26 STATE=WAKEUP [24.833475] swimcu_calibrate_event_handle: MCU calibrate completed with remaining time 0 [24.833500] swimcu_lpo_calibrate_calc: MCU time=25000 vs MDM time=24402 [24.833518] gpio_check_and_wake: wake-n_gpio26 STATE=SLEEP [31.581249] usb 1-1: device descriptor read/64, error -110 [31.811255] usb 1-1: new high-speed USB device number 3 using msm_hsic_host [46.991241] usb 1-1: device descriptor read/64, error -110 [62.281241] usb 1-1: device descriptor read/64, error -110 [62.511251] usb 1-1: new high-speed USB device number 4 using msm_hsic_host [72.971251] usb 1-1: device not accepting address 4, error -110 [73.090779] usb 1-1: new high-speed USB device number 5 using msm_hsic_host [83.551236] usb 1-1: device not accepting address 5, error -110 [83.551479] usb usb1-port1: unable to enumerate USB device [83.552259] msm_hsic_host 7c00000.hsic_host: HSIC-USB in low power mode [110.736727] sh (1643) used greatest stack depth: 4468 bytes left [121.121195] sierra_startup_monitor ``` **cm info** output: > ``` > Device: WP7607-1 > IMEI: > IMEISV: 5 > FSN: > Firmware Version: SWI9X07Y_02.18.05.00 000000 jenkins 2018/07/19 17:40:21 > Bootloader Version: SWI9X07Y_02.18.05.00 000000 jenkins 2018/07/19 17:40:21 > MCU Version: 002.009 > PRI Part Number (PN): 9907364 > PRI Revision: 001.004 > Carrier PRI Name: GENERIC > Carrier PRI Revision: 002.041_002 > SKU: 1103529 > Last Reset Cause: Power Down > Resets Count: Expected: 6 Unexpected: 0 > > ``` Thanks ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/jyijyi/32/822_2.png) [@jyijyi](https://forum.legato.io/u/jyijyi)\ **Post date:** [August 26, 2019, 1:38am UTC](https://forum.legato.io/t/usb-flash-not-detected-in-dev/4644/2 "2019-08-26T01:38:51Z")
are you using MangOH red board? I tried here, no problem is found for WP7607 on MangOH red board. When I inserted the USB thumb drive, it can always detect. Have you also checked if this is related to power issue? * * * root@swi-mdm9x28-wp:~# ls /dev/sda\* /dev/sda /dev/sda1 root@swi-mdm9x28-wp:~# root@swi-mdm9x28-wp:~# cm info Device: WP7607 IMEI: 359779081234565 IMEISV: 9 FSN: VN730485080103 Firmware Version: SWI9X07Y\_02.32.01.00 000000 jenkins 2019/08/19 10:22:59 Bootloader Version: SWI9X07Y\_[101.822968] i2c-msm-v2 78b8000.i2c: NACK: slave not responding, ensure its powered: msgs(n:1 cur:0 tx) bc(rx:0 tx:2) mode:FIFO slv\_addr:0x3a MSTR\_STS:0x0c1300c8 OPER:0x00000090 02.32.01.00 000000 jenkins 2019/08/19 10:22:59 [101.843270] i2c-msm-v2 78b8000.i2c: NACK: slave not responding, ensure its powered: msgs(n:1 cur:0 tx) bc(rx:0 tx:2) mode:FIFO slv\_addr:0x3a MSTR\_STS:0x0c1300c8 OPER:0x00000090 MCU Version: 002.013 PRI Part Number (PN): 9908958 PRI Revision: 001.000 Carrier PRI Name: GENERIC Carrier PRI Revision: 002.078\_000 SKU: 1104301 Last Reset Cause: Reset, User Requested Resets Count: Expected: 5 Unexpected: 0 ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/jyijyi/32/822_2.png) [@jyijyi](https://forum.legato.io/u/jyijyi)\ **Post date:** [August 26, 2019, 9:17am UTC](https://forum.legato.io/t/usb-flash-not-detected-in-dev/4644/4 "2019-08-26T09:17:47Z")
Is that if you burn the offical cwe FW, no problem is found for the USB flash enumeration? ---
**Author:** ![MilanVidic](https://avatars.discourse-cdn.com/v4/letter/m/e480ec/32.png) [@MilanVidic](https://forum.legato.io/u/MilanVidic)\ **Post date:** [August 26, 2019, 10:01am UTC](https://forum.legato.io/t/usb-flash-not-detected-in-dev/4644/5 "2019-08-26T10:01:52Z")
I edited my original post to better describe the problem. Thank you ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/jyijyi/32/822_2.png) [@jyijyi](https://forum.legato.io/u/jyijyi)\ **Post date:** [August 26, 2019, 10:11am UTC](https://forum.legato.io/t/usb-flash-not-detected-in-dev/4644/6 "2019-08-26T10:11:44Z")
best case is that you try on mangOH red board to see if this is hardware related.