Index: README |
diff --git a/README b/README |
index f67e3611619b4aa4c356417895af4ebd816381b6..6fe143e759c619798c4ada616112457ffe1cadb1 100644 |
--- a/README |
+++ b/README |
@@ -14,10 +14,15 @@ controller interface, using libusb to access the host |
controller. |
If you're more interested in the MTP responders, gadgets like |
-MP3 players, mobile phones etc, look into MeeGo:s Buteo Sync: |
-http://wiki.meego.com/Buteo - these guys are creating a fully |
-open source MTP responder. |
- |
+MP3 players, mobile phones etc, look into: |
+- MeeGo:s Buteo Sync: |
+ https://github.com/nemomobile/buteo-mtp |
+ https://wiki.merproject.org/wiki/Buteo/MTP |
+- Android has an MTP responder implementation: |
+ https://android.googlesource.com/platform/frameworks/base/+/master/media/jni/ |
+- Ubuntu/Ricardo Salveti has mtp-server and libmtp-server going: |
+ https://code.launchpad.net/~phablet-team/mtp/trunk |
+ http://bazaar.launchpad.net/~phablet-team/mtp/trunk/files |
Heritage |
-------- |
@@ -138,6 +143,25 @@ Some MTP devices have strange pecularities. We try to work around |
these whenever we can, sometimes we cannot work around it or we |
cannot test your solution. |
+* Android locked screen: some devices just report zero files |
+ and no storages when the device screen is locked, it looks like |
+ so: |
+ |
+ mtp-detect |
+ Device 0 (VID=04e8 and PID=6860) is a Samsung Galaxy models (MTP). |
+ Attempting to connect device(s) |
+ Error 1: Get Storage information failed. |
+ Device: SHV-E210K |
+ LIBMTP_Get_Storage(): No data available |
+ OK. |
+ |
+ This is probably so as not to allow the MTP access to be used |
+ as a "backdoor" into the device. Unlock the device before listing |
+ files, set the autolock to some large value or disabled if it |
+ disturbs you, you are causing this to yourself, or should we say |
+ that your vendor is prioritizing security and privacy over |
+ ease-of-use. (You may talk to your vendor about this.) |
+ |
* mtp-* tools doesn't work because someone else is already hogging |
the device |
@@ -150,10 +174,12 @@ cannot test your solution. |
Then re-attach the device. |
- Sometimes the "gvfs-gphoto2-volume-monitor" is running on the |
- system and hogging the device, try something like: |
+ Sometimes some gvfs daemons are running on the |
+ system and hogging the device, try stopping them |
+ with something like these commands: |
- pkill gfvs-gphoto2-volume-monitor |
+ killall gvfs-mtp-volume-monitor |
+ killall gvfs-gphoto2-volume-monitor |
Then plug in the device and issue "mtp-detect" to figure out if |
this may be the case. |
@@ -205,13 +231,6 @@ cannot test your solution. |
manufacturer and ask them to test their product with some libmtp |
program. |
-* Android locked screen: some devices just report zero files |
- and no storages when the device is locked, probably so as not |
- to allow the MTP access to be used as a "backdoor" into the |
- device. Unlock the device before listing files, set the autolock |
- to some large value or disabled if it disturbs you, you are |
- causing this to yourself. |
- |
* Samsung Android 2.3.x devices: these have a special MTP stack |
with some specific bugs that we have maybe nailed down now. |
It suffers from an "immediate connect" syndrome, i.e. you have |
@@ -579,19 +598,30 @@ Here is what some people do: |
6. Once mtp-detect gives you an "Ok", open either Rhythmbox or Gnomad2, |
everything should work. |
-Linux: Try this, if you have a recent 2.6.x Linux kernel, |
-run (as root) something like: |
+Linux: Try this, if you have a recent Linux kernel, |
+add the file (as root): |
+ |
+/etc/modprobe.d/no-usb-storage.conf |
+ |
+With the contents: |
+ |
+options usb-storage quirks=1234:4321:i |
+ |
+This will tell usb-storage to ignore this device when it's inserted |
+so it is not hogged by the mass storage interfaces. Remove and re-insert |
+the device and see if it works. Usually this does the trick. |
+ |
+For older systems, or as a bigger hammer, run (as root) something |
+like: |
> rmmod usb_storage ; mtp-detect |
You can run most any command or a client like gnomad2 or |
Amarok immediately after the rmmod command. This works |
-sometimes. Another way: |
+sometimes. Another even more brutal approach is this: |
* Edit /etc/modprobe.d/blacklist |
- |
* Add the line "blacklist usb-storage" |
- |
* Reboot. |
Now none of you USB disks, flash memory sticks etc will be |
@@ -998,18 +1028,45 @@ builders summit, might come to recycle this: |
- Protocol overview |
- Transactional filesystem - no corruption due to unplugged cables! |
+ - The host and the device can access the files simultaneously, the |
+ device will always "own" the physical file system and proxy the |
+ host (MTP initiator). |
- libmtp interface |
- relation to libgphoto2 |
- User expectations fall short: |
- Not really a mountable filesystem. |
- Streaming does not work. (Size needs to be known beforehand due to |
transactional nature.) |
+ - GVFS MTP backend to the rescue. |
- Device sins |
+ - Using the same VID/PID for several modes, some of which are not MTP. |
+ HTC Zopo, HD2, Bird (0x0bb4/0x0c02). Thanks for that, now we cannot |
+ detect the protocol from just VID+PID but have to examine the interfaces. |
- Android bugs |
- Samsungs special Android MTP stack |
- SonyEricsson Aricent stack for Xperia Androids pre 4.0, broken headers! |
- Flat access model vs hierarchical, how Android uses MTP as an hierachical |
file system while it was previously a flat database. |
+ - Old paradigm: scan the entire non-hierarchical storage for all content, |
+ build a cache to speed up the (USB 1.1!) link. Usually all files were |
+ stored in the root folder or a single folder named "/Music" or similar. |
+ - Android introduced deeply nested folder hierarchies, not seen before |
+ on MTP devices. |
+ - Microsoft not using the complete metadata dump feature of the MTP |
+ protocol (once introduced by creative) instead they walk directories |
+ separately. |
+ - So caching a big device will take long time and/or timeout. |
+ - Go-MTPFS (FUSE) and GVFS MTP - doing the partial directory walk rather |
+ than caching all files. |
+ - Especially Android devices nowadays assume that |
+ you want to index a folder at the time, whereas older MTP devices (such |
+ as those from Creative) would assume that you wanted to index the entire |
+ device as it was plugged in, and device firmware is now ever more tailored |
+ toward per-folder filetree walking. This makes it harder for the library |
+ to provide the right abstractions: do we provide an API for indexing the |
+ whole device which is unacceptably slow on new devices, or do we provide |
+ an API for indexing a directory at the time which will somehow work on |
+ older devices too? Shall we deprecate the older API? |
- Detecting from vendor extension, can fix in newer extensions! |
- Autoprobing on Linux |
- Color devices do not like autoprobing |
@@ -1018,7 +1075,8 @@ builders summit, might come to recycle this: |
- Multimode USB - one PID for each mode due to Windows limitations not |
applicable to Linux, SONY devices have ~5 different PIDs for a single |
device. |
- - Mode switch devices? |
-- MTPZ |
+ - Mode switch devices? Maybe we do this wrong. |
+- MTPZ, came and went. Apparently deprecated by Microsoft with Windows |
+ Phone 8. |
- Ideas?? |