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Cherry Trail Z8750 USB3.0 xhci Compatibility USB3.0 flash issue on Android 7.1


Hello, We are facing an issue that Cherry Trail Z8750 USB3.0 xhci root hub has USB3.0 flashes compatibility issue while Android 7.1 boots up.

some of usb3.0 flashes 100% cannot be recognized while Android 7.1 boots up.

However, after android 7.1 is boot and ready, I unplug USB3.0 flash and plug in again the USB3.0 flash can be recognized.

I use dmesg to dump debug message and I found that xhci hcd root hub CAN recognized USB3.0 flash at beginning, but there always is a remove INT occurred. the driver starts do debounce check and remove USB3.0 flash although the USB3.0 flash is still attached on my device.

below is the debug message, it shows

at 6.923130 sec the driver found an USB3.0 at hub 2-0:1.0 and finish connection

at 7.202915 sec the driver found an Hub change at hub 2-0:1.0 and starts denounce check with no USB3.0 device result.

the USB3.0 device is present or not always come from xhci hcd root hub.

Although I tried reset root hub or USB device, USB3.0 flash always cannot be recognized while Android boots up.

I also install and test my device on Windows 10 with the Same USB3.0 Flashes, they are work perfectly!!

Is there any work around solution?


[ 0.000000] Initializing cgroup subsys cpuset

[ 0.000000] Initializing cgroup subsys cpu

[ 0.000000] Initializing cgroup subsys cpuacct

[ 0.000000] Linux version 3.14.79-x86_64-svn6727 (Flytech@ANDROID) (gcc version 4.9.2 (GCC) ) # 131 SMP PREEMPT Wed Jul 25 09:17:03 CST 2018

[ 0.000000] Command line: androidboot.bootloader=d420v101_d420-10103__kernelflinger-04_15-userdebug androidboot.diskbus=10.0 androidboot.verifiedbootstate=green androidboot.bootreason=power_button_pressed androidboot.serialno=androidd410123456789 g_ffs.iSerialNumber=androidd410123456789 enforcing=0 androidboot.selinux=permissive loglevel=5 androidboot.hardware=cht_rvp firmware_class.path=/system/etc/firmware memmap=4M$0x5c400000 vga=current i915.modeset=1 drm.vblankoffdelay=1 i915.fastboot=1 thermal.off=1 console=ttyS0,115200n8 pstore.backend=ramoops intel_pstore_pram.record_size=0x8000

[ 0.000000] e820: BIOS-provided physical RAM map:

[ 0.000000] BIOS-e820: [mem 0x0000000000000000-0x000000000008efff] usable

[ 0.000000] BIOS-e820: [mem 0x000000000008f000-0x000000000008ffff] ACPI NVS

[ 0.000000] BIOS-e820: [mem 0x0000000000090000-0x000000000009ffff] usable

[ 0.000000] BIOS-e820: [mem 0x0000000000100000-0x000000001effffff] usable

[ 0.000000] BIOS-e820: [mem 0x000000001f000000-0x00000000201fffff] reserved

[ 0.000000] BIOS-e820: [mem 0x0000000020200000-0x000000007a49dfff] usable

[ 0.000000] BIOS-e820: [mem 0x000000007a49e000-0x000000007adddfff] reserved

[ 0.000000] BIOS-e820: [mem 0x000000007adde000-0x000000007aeddfff] ACPI NVS

[ 0.000000] BIOS-e820: [mem 0x000000007aede000-0x000000007af1dfff] ACPI data

[ 0.000000] BIOS-e820: [mem 0x000000007af1e000-0x000000007bffffff] usable

[ 0.000000] BIOS-e820: [mem 0x00000000e0000000-0x00000000e3ffffff] reserved

[ 0.000000] BIOS-e820: [mem 0x00000000fea00000-0x00000000feafffff] reserved

[ 0.000000] BIOS-e820: [mem 0x00000000fec00000-0x00000000fec00fff] reserved

[ 0.000000] BIOS-e820: [mem 0x00000000fed01000-0x00000000fed01fff] reserved

[ 0.000000] BIOS-e820: [mem 0x00000000fed03000-0x00000000fed03fff] reserved

[ 0.000000] BIOS-e820: [mem 0x00000000fed06000-0x00000000fed06fff] reserved

[ 0.000000] BIOS-e820: [mem 0x00000000fed08000-0x00000000fed09fff] reserved

[ 0.000000] BIOS-e820: [mem 0x00000000fed1c000-0x00000000fed1cfff] reserved

[ 0.000000] BIOS-e820: [mem 0x00000000fed80000-0x00000000fedbffff] reserved

[ 0.000000] BIOS-e820: [mem 0x00000000fee00000-0x00000000fee00fff] reserved

[ 0.000000] BIOS-e820: [mem 0x00000000ffc00000-0x00000000ffffffff] reserved

[ 0.000000] BIOS-e820: [mem 0x0000000100000000-0x000000017fffffff] usable

[ 0.000000] NX (Execute Disable) protection: active

[ 0.000000] e820: user-defined physical RAM map:

[ 0.000000] user: [mem 0x0000000000000000-0x000000000008efff] usable

[ 0.000000] user: [mem 0x000000000008f000-0x000000000008ffff] ACPI NVS

[ 0.000000] user: [mem 0x0000000000090000-0x000000000009ffff] usable

[ 0.000000] user: [mem 0x0000000000100000-0x000000001effffff] usable

[ 0.000000] user: [mem 0x000000001f000000-0x00000000201fffff] reserved

[ 0.000000] user: [mem 0x0000000020200000-0x000000005c3fffff] usable

[ 0.000000] user: [mem 0x000000005c400000-0x000000005c7fffff] reserved

[ 0.000000] user: [mem 0x000000005c800000-0x000000007a49dfff] usable

[ 0.000000] user: [mem 0x000000007a49e000-0x000000007adddfff] reserved

[ 0.000000] user: [mem 0x000000007adde000-0x000000007aeddfff] ACPI NVS

[ 0.000000] user: [mem 0x000000007aede000-0x000000007af1dfff] ACPI data

[ 0.000000] user: [mem 0x000000007af1e000-0x000000007bffffff] usable

[ 0.000000] user: [mem 0x00000000e0000000-0x00000000e3ffffff] reserved

[ 0.000000] user: [mem 0x00000000fea00000-0x00000000feafffff] reserved

[ 0.000000] user: [mem 0x00000000fec00000-0x00000000fec00fff] reserved

[ 0.000000] user: [mem 0x00000000fed01000-0x00000000fed01fff] reserved

[ 0.000000] user: [mem 0x00000000fed03000-0x00000000fed03fff] reserved

[ 0.000000] user: [mem 0x00000000fed06000-0x00000000fed06fff] reserved

[ 0.000000] user: [mem 0x00000000fed08000-0x00000000fed09fff] reserved

[ 0.000000] user: [mem 0x00000000fed1c000-0x00000000fed1cfff] reserved

[ 0.000000] user: [mem 0x00000000fed80000-0x00000000fedbffff] reserved

[ 0.000000] user: [mem 0x00000000fee00000-0x00000000fee00fff] reserved

[ 0.000000] user: [mem 0x00000000ffc00000-0x00000000ffffffff] reserved

[ 0.000000] user: [mem 0x0000000100000000-0x000000017fffffff] usable

[ 0.000000] efi: EFI v2.40 by INSYDE Corp.

[ 0.000000] efi: ACPI 2.0=0x7af1d014 SMBIOS=0x7a56d000

[ 0.000000] efi: mem00: type=7, attr=0xf, range=[0x0000000000000000-0x000000000008f000) (0MB)

[ 0.000000] efi: mem01: type=10, attr=0xf, range=[0x000000000008f000-0x0000000000090000) (0MB)

[ 0.000000] efi: mem02: type=2, attr=0xf, range=[0x0000000000090000-0x0000000000092000) (0MB)

[ 0.000000] efi: mem03: type=7, attr=0xf, range=[0x0000000000092000-0x000000000009f000) (0MB)

[ 0.000000] efi: mem04: type=2, attr=0xf, range=[0x000000000009f000-0x00000000000a0000) (0MB)

[ 0.000000] efi: mem05: type=2, attr=0xf, range=[0x0000000000100000-0x0000000000632000) (5MB)

[ 0.000000] efi: mem06: type=7, attr=0xf, range=[0x0000000000632000-0x0000000001000000) (9MB)

[ 0.000000] efi: mem07: type=2, attr=0xf, range=[0x0000000001000000-0x0000000002ad0000) (26MB)

[ 0.000000] efi: mem08: type=7, attr=0xf, range=[0x0000000002ad0000-0x000000001f000000) (453MB)

[ 0.000000] efi: mem09: type=0, attr=0xf, range=[0x000000001f000000-0x0000000020200000) (18MB)

[ 0.000000] efi: mem10: type=7, attr=0xf, range=[0x0000000020200000-0x000000003fffc000) (509MB)

[ 0.000000] efi: mem11: type=2, attr=0xf, range=[0x000000003fffc000-0x0000000040000000) (0MB)

[ 0.000000] efi: mem12: type=7, attr=0xf, range=[0x0000000040000000-0x0000000073d3e000) (829MB)

[ 0.000000] efi: mem13: type=4, attr=0xf, range=[0x0000000073d3e000-0x0000000073d5e000) (0MB)

[ 0.000000] efi: mem14: type=7, attr=0xf, range=[0x0000000073d5e000-0x00000000759b7000) (28MB)

[ 0.000000] efi: mem15: type=2, attr=0xf, range=[0x00000000759...

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2 Replies

Hello, Ethan_Ma:

Thank you for contacting Intel Embedded Community.

In order to help you please address your request by filling out the https://www.intel.com/content/www/us/en/secure/forms/design-assistance.html Embedded Design Assistance form.

On the other hand, it is important to let you know that unfortunately the Cherry Trail is on the "off-roadmap" and its support is for limited manufacturers. For this reason, this processor family is unsupported by this channel. Click onhttps://ark.intel.com/products/codename/46629/Cherry-Trail Cherry Trail website to learn more about the specifications of this family.

We hope that this information is useful to you.

Best Regards,


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Hello Carlos,

Thank you for your information, I am going to filling out the form.

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