diff options
| author | Vincent Pelletier <plr.vincent@gmail.com> | 2016-12-15 12:47:41 +0000 |
|---|---|---|
| committer | Felipe Balbi <felipe.balbi@linux.intel.com> | 2017-01-02 10:55:28 +0200 |
| commit | 96a420d2d37cc019d0fbb95c9f0e965fa1080e1f (patch) | |
| tree | 1d72daa782156faeae0244b0611c745b3d546929 | |
| parent | 7e4da3fcf7c9fe042f2f7cb7bf23861a899b4a8f (diff) | |
usb: gadget: f_fs: Document eventfd effect on descriptor format.
When FUNCTIONFS_EVENTFD flag is set, __ffs_data_got_descs reads a 32bits,
little-endian value right after the fixed structure header, and passes it
to eventfd_ctx_fdget. Document this.
Also, rephrase a comment to be affirmative about the role of string
descriptor at index 0. Ref: USB 2.0 spec paragraph "9.6.7 String", and
also checked to still be current in USB 3.0 spec paragraph "9.6.9 String".
Signed-off-by: Vincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
| -rw-r--r-- | drivers/usb/gadget/function/f_fs.c | 4 | ||||
| -rw-r--r-- | include/uapi/linux/usb/functionfs.h | 1 |
2 files changed, 3 insertions, 2 deletions
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index aab3fc1dbb94..818f4997c1ac 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -2091,8 +2091,8 @@ static int __ffs_data_do_entity(enum ffs_entity_type type, case FFS_STRING: /* - * Strings are indexed from 1 (0 is magic ;) reserved - * for languages list or some such) + * Strings are indexed from 1 (0 is reserved + * for languages list) */ if (*valuep > helper->ffs->strings_count) helper->ffs->strings_count = *valuep; diff --git a/include/uapi/linux/usb/functionfs.h b/include/uapi/linux/usb/functionfs.h index acc63697a0cc..b2a31a55a612 100644 --- a/include/uapi/linux/usb/functionfs.h +++ b/include/uapi/linux/usb/functionfs.h @@ -93,6 +93,7 @@ struct usb_ext_prop_desc { * | 0 | magic | LE32 | FUNCTIONFS_DESCRIPTORS_MAGIC_V2 | * | 4 | length | LE32 | length of the whole data chunk | * | 8 | flags | LE32 | combination of functionfs_flags | + * | | eventfd | LE32 | eventfd file descriptor | * | | fs_count | LE32 | number of full-speed descriptors | * | | hs_count | LE32 | number of high-speed descriptors | * | | ss_count | LE32 | number of super-speed descriptors | |