1181401 - USB Mass Storage warning does not say what happens if I don't have an SD card

Status: RESOLVED INCOMPLETE

(Firefox OS Graveyard :: Gaia::Settings, defect)

Description

[:Atoll]

When I try to enable USB Mass Storage, it says "will only work correctly with an external SD card". But I don't have an external SD card inserted.

Is it still safe to press "OK"? Why does it say "Warning: USB Mass Storage may not work" when the messaging seems confident that it will, without exception, fail?

Comment 1

[Dave Hylands [:dhylands]]

UMS can only share the external sdcard on the z3c device.

So nothing bad will happen if no sdcard is present, but since there is no sdcard, you also won't see anything on the host.

The wording could probably be improved.

Comment 2

[Tiffanie Shakespeare [:tif]]

Passing NI to Harly. I think this could use a little more than just a string revision. It doesn't seem to make sense to allow the user to pick USB Mass Storage if it won't work b/c there isn't an SDCard.

Thanks and sorry for the delay!

Comment 3

[Harly Hsu[:harly]]

Hi Dave,
I am just curious that is there a reason why we can not share internal SDcard in Z3C in UMS mode?
Just want to make sure we have everything considered before making a design change. Thanks

Comment 4

[Dave Hylands [:dhylands]]

Sharing the internal sdcard using UMS requires that the internal sdcard be a dedicated vfat formatted partition.

The way that the z3c (and most kitkat and onwards phones) is setup, /data, and the internal sdcard are sharing an ext4 formatted partition, and thus can't be shared using UMS.

The nexus4 and nexus5 also behave this way.

Comment 5

[Harly Hsu[:harly]]

OK, below are my comments on this:
1. Modify the wording: Remove the title "Warning: USB Mass Storage may not work" from the dialog to avoid confusion
2. Disable UMS mode if there is no external sdcard on device like Z3C and auto change to MTP mode
3. If users had previously selected UMS mode and removed the external sdcard, once users plugin the external sdcard back, system will auto change from MTP mode back to UMS mode.

Does that make sense?

Comment 6

[[e-mail]]

ni Dave for wording feedback

Comment 7

[Dave Hylands [:dhylands]]

So for point 3, that sounds like you need a new setting? It may no be exposed to the user, but I think you'd need it order to implement this. And presumably, that will require changes in the AutoMounter.

It's like there is a setting to use when the external sdcard is plugged in, and one to use when the external card is not plugged in. 

As far as wording goes, I'm not completely sure.

Something like "UMS mode only works with the external sdcard. Use MTP mode to access both internal and external sdcards." But I think that a UI person should choose the correct wording.

The difference between "USB Storage" and "USB Mass Storage" will be lost on most people, so personally, I'd be inclined to call the modes UMS versus MTP.

Comment 8

[:Atoll]

My cameras over the past few years have listed the options "Mass Storage", "PTP", "PTP/MTP", and "MTP". I've never seen UMS before and wouldn't know what it meant if not for this conversation, so I strongly advise "Mass Storage" rather than "UMS".