MTP doesn't work. Build Info: Build ID 20141218151450 Gaia Revision 58734e8a48157f99d5b733412b600c2e04c954fe Gaia Date 2014-12-18 05:21:04 Gecko Revision n/a Gecko Version 37.0a1 Device Name hammerhead Firmware(Release) 5.0 Firmware(Incremental) eng.askeing.20141218.150855 Firmware Date Thu Dec 18 15:10:01 CST 2014 Bootloader HHZ12d

MTP sometimes dosen't work on Nexus 5, it's not stable. It seems like a bug, not a porting blocker issue. Alphan will help to find the root cause.

From log, when error happened, the state of automounter keep in "UMS_CONFIGURING". Since Nexus 5 is a fuse architecture, we cannot use UMS on Nexus 5.

Here is the automounter and mtp log.

Hi Alphan, Are you gonna take it? would also need ETA for better understanding the risk. thanks.

Yes, I will take this bug.

The following is the reason of why MTP cannot restart successfully. When restarting MozMtpServer, "/dev/mtp_usb" cannot be opened. (the error code is "Device or resource busy") 12-18 15:21:40.937 193 423 I AutoMounter: Changing mode from 'Enable-MTP' to 'Disable' 12-18 15:21:40.937 193 423 I AutoMounter: Stopping MtpServer 12-18 15:21:40.937 193 423 I MozMtp : ~MozMtpStorage: Storage destructed for Volume sdcard mStorageID 0x00010001 12-18 15:21:40.937 193 423 I MozMtp : StorageUnavailable: Removing mStorageID 0x00010001 from MtpServer 12-18 15:21:40.937 193 423 I MozMtp : StorageUnavailable: Removing mStorageID 0x00010001 from MozMtpDatabse 12-18 15:21:40.937 193 423 I AutoMounter: AutoMounter state changed from MTP_STARTED to IDLE 12-18 15:21:40.937 193 423 I AutoMounter: UpdateState: ums:A0C0E0 mtp:A1C1E0 mode:0 usb:1 tryToShare:0 state:IDLE 12-18 15:21:40.937 193 423 I AutoMounter: UpdateState: Volume sdcard is Mounted and inserted @ /storage/emulated/legacy gen 1 locked 0 sharing x 12-18 15:21:40.937 193 423 I AutoMounterSetting: Changing status from 'Enabled' to 'Disabled' 12-18 15:21:47.250 193 423 I AutoMounter: Changing mode from 'Disable' to 'Enable-MTP' 12-18 15:21:47.250 193 423 I AutoMounter: Starting MtpServer 12-18 15:21:47.250 193 423 E MozMtp : Init: open of '/dev/mtp_usb' failed

/dev/mtp_usb is busy when server is still running. class MtpServerRunnable : public nsRunnable { ... nsresult Run() { ... MTP_LOG("MozMtpServer started"); server->run(); MTP_LOG("MozMtpServer finished"); ... } ... private: nsRefPtr<MozMtpServer> mMozMtpServer; ScopedClose mMtpUsbFd; // We want to hold this open while the server runs }

The patch contain the three parts: 1. Add one case for disabling MTP on fuse device. 2. Need to set sMozMtpServer as nullptr when "sMozMtpServer->Init()" failed. 3. Print the reason of opening "/dev/mtp_usb" failed.

Update a new version.

Comment on attachment 8543743 [details] [diff] [review] [automounter] Add a case for fuse and add some useful logs-0105 Review of attachment 8543743 [details] [diff] [review]: ----------------------------------------------------------------- Looks good - just a couple minor nits to address. ::: dom/system/gonk/AutoMounter.cpp @@ +105,5 @@ > #define USB_FUNC_MTP "mtp" > #define USB_FUNC_NONE "none" > #define USB_FUNC_RNDIS "rndis" > #define USB_FUNC_UMS "mass_storage" > +#define USB_FUNC_DFT "default" nit: Since we're introducing a "fake" USB Function, let's choose a name like ~~default~~ or something that isn't likely to ever be used in real life. nit: Let's use USB_FUNC_DEFAULT rather than abbreviating to DFT

Here is the try server result. It looks fine. https://treeherder.mozilla.org/#/jobs?repo=try&revision=bf08c0362bfc

Could you please also land the patch to v2.2? Thanks.

Sure. I will do the test by myself first and request the approval for v2.2 later.

Comment on attachment 8555140 [details] [diff] [review] [automounter] Add a case for fuse and add some useful logs. r=dhylands [Approval Request Comment] Bug caused by (feature/regressing bug #): It is a lack of MTP implementation. User impact if declined: The MTP functionality may be broken when doing enable and disable frequently. Testing completed: MTP testcases(http://goo.gl/pZIds0) are passed. Risk to taking this patch (and alternatives if risky): (low risk) It is a patch for the lack. String or UUID changes made by this patch: none