Messages in this thread | | | From | Michal Nazarewicz <> | Subject | Re: [PATCH] usb: gadget: f_fs: add "zombie" mode | Date | Mon, 06 Oct 2014 14:36:15 +0200 |
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On Mon, Oct 06 2014, Robert Baldyga <r.baldyga@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.baldyga@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
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