On 10/06/2014 02:36 PM, Michal Nazarewicz wrote:
> On Mon, Oct 06 2014, Robert Baldyga <r.baldyga@xxxxxxxxxxx> 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?
Shouldn't be error-prone, because opening them will fail with -ENODEV,
but indeed it can be confusing. I will try to do something about that :)
>
>>
>> Signed-off-by: Robert Baldyga <r.baldyga@xxxxxxxxxxx>
>> ---
>> 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
>
Thanks,
Robert Baldyga
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