Re: [Libmtp-discuss] libmtp error: could not get object handles for some directories

[Philip L. <ph...@ov...>]

On 2018-05-13 23:29, Andrea Vai wrote:
> 
>> You can override the device timeout value, and libmtp actually does
>> this in a different call that retrieves the list of all files on the
>> device. The gvfs code that is relevant in your example is only
>> getting
>> the file list for a single directory but if the device has a silly
>> default timeout (likely - thank's samsung), it might still hit it.
>> So
>> I'd try setting a larger timeout and see if it helps. If that does
>> help, you can then look at implementing it as a device quirk.
>> 
>> See get_all_metadata_fast for the current usage and then look at
>> LIBMTP_Get_Files_And_Folders for where you'd want to adjust the
>> timeout
>> (around the call to ptp_getobjecthandles).
> 
> Thank you for your kind reply, Phil. I downloaded the current source
> code and found the strings you mention in libmtp.c. I guess I should
> increase the "60000" value at line 2620. Though, I am not skilled in
> linux development, so some further hints would be greatly appreciated
> (should I change the value, remove my libmtp installed package, build
> and install the hacked source code, and try if it works?). In the
> meantime, I will try to figure it out.

Hi Andrea,

No - you want to apply the same technique used in get_all_metadata_fast 
in
LIBMTP_Get_Files_and_Folders, so set the timeout to 60000 before the 
call
to ptp_getobjecthandles and then restore it to the previous value 
afterwards.

As for testing it out, the most robust way would be to build it and then 
add
a file in /etc/ld.so.config.d/ which lists the location of your built 
libmtp.so.
Then after you run `ldconfig`, it should have higher priority than the 
installed
library. You can verify this by running ldd on the gvfsd-mtp binary.

--phil