bybrooklyn/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-04-18 06:44:00 -04:00
Code Issues Packages Projects Releases Wiki Activity

usb: gadget: f_fs: expose ready state in configfs

Browse Source 
When a USB gadget is configured through configfs with 1 or more f_fs
functions, then the logic setting up the gadget configuration has to wait
until the user space code (typically separate applications) responsible for
those functions have written their descriptors before the gadget can be
activated.

The f_fs instance already knows if this has been done, so expose it through
a "ready" attribute in configfs for easier synchronization.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Link: https://lore.kernel.org/r/20240126203208.2482573-1-peter@korsgaard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Peter Korsgaard
2024-01-26 21:32:08 +01:00
committed by Greg Kroah-Hartman
parent 2d2a334952
commit 43a029724d
3 changed files with 38 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
Documentation/usb/gadget-testing.rst
View File

@@ -206,6 +206,14 @@ the standard procedure for using FunctionFS (mount it, run the userspace
process which implements the function proper). The gadget should be enabled
by writing a suitable string to usb_gadget/<gadget>/UDC.
The FFS function provides just one attribute in its function directory:
ready
The attribute is read-only and signals if the function is ready (1) to be
used, E.G. if userspace has written descriptors and strings to ep0, so
the gadget can be enabled.
Testing the FFS function
------------------------