On Mon, Oct 06 2014, Robert Baldyga <r.bald...@samsung.com> wrote:
> Since we can compose gadgets from many functions, there is the problem
> related to gadget breakage while FunctionFS daemon being closed. In some
> cases it's strongly desired to keep gadget alive for a while, despite
> FunctionFS files are closed, to allow another functions to complete
> some presumably critical operations.
>
> For this purpose this patch introduces "zombie" mode. It can be enabled
> by setting mount option "zombie=1", and results with defering function
> closure to the moment of reopening ep0 file or filesystem umount.
>
> When ffs->state == FFS_ZOMBIE:
> - function is still binded and visible to host,
> - setup requests are automatically stalled,
> - all another transfers are refused,
> - opening ep0 causes function close, and then FunctionFS is ready for
> descriptors and string write,
> - umount of functionfs cause function close.
However, all the ep# files will still exist on the filesystem. This may
be a bit confusing and error-prone, no?
>
> Signed-off-by: Robert Baldyga <r.bald...@samsung.com>
> ---
> drivers/usb/gadget/function/f_fs.c | 25 ++++++++++++++++++++++---
> drivers/usb/gadget/function/u_fs.h | 4 ++++
> 2 files changed, 26 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/gadget/function/f_fs.c
> b/drivers/usb/gadget/function/f_fs.c
> @@ -1222,6 +1225,12 @@ static int ffs_fs_parse_opts(struct ffs_sb_fill_data
> *data, char *opts)
>
> /* Interpret option */
> switch (eq - opts) {
> + case 6:
> + if (!memcmp(opts, "zombie", 6))
> + data->zombie_mode = !!value;
Unnecessary double space before =.
> + else
> + goto invalid;
> + break;
> case 5:
> if (!memcmp(opts, "rmode", 5))
> data->root_mode = (value & 0555) | S_IFDIR;
> diff --git a/drivers/usb/gadget/function/u_fs.h
> b/drivers/usb/gadget/function/u_fs.h
> @@ -92,6 +92,8 @@ enum ffs_state {
> */
> FFS_ACTIVE,
>
> + FFS_ZOMBIE,
> +
Add comment describing the state.
> /*
> * All endpoints have been closed. This state is also set if
> * we encounter an unrecoverable error. The only
--
Best regards, _ _
.o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o
..o | Computer Science, Michał “mina86” Nazarewicz (o o)
ooo +--<m...@google.com>--<xmpp:min...@jabber.org>--ooO--(_)--Ooo--
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