Hi Sasha, Sasha Levin wrote: > From: EJ Hsu <ejh@xxxxxxxxxx> > > [ Upstream commit e70b3f5da00119e057b7faa557753fee7f786f17 ] > > This change is to fix below warning message in following scenario: > usb_composite_setup_continue: Unexpected call > > When system tried to enter suspend, the fsg_disable() will be called to > disable fsg driver and send a signal to fsg_main_thread. However, at > this point, the fsg_main_thread has already been frozen and can not > respond to this signal. So, this signal will be pended until > fsg_main_thread wakes up. > > Once system resumes from suspend, fsg_main_thread will detect a signal > pended and do some corresponding action (in handle_exception()). Then, > host will send some setup requests (get descriptor, set configuration...) > to UDC driver trying to enumerate this device. During the handling of "set > configuration" request, it will try to sync up with fsg_main_thread by > sending a signal (which is the same as the signal sent by fsg_disable) > to it. In a similar manner, once the fsg_main_thread receives this > signal, it will call handle_exception() to handle the request. > > However, if the fsg_main_thread wakes up from suspend a little late and > "set configuration" request from Host arrives a little earlier, > fsg_main_thread might come across the request from "set configuration" > when it handles the signal from fsg_disable(). In this case, it will > handle this request as well. So, when fsg_main_thread tries to handle > the signal sent from "set configuration" later, there will nothing left > to do and warning message "Unexpected call" is printed. > > Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> > Signed-off-by: EJ Hsu <ejh@xxxxxxxxxx> > Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> > --- > drivers/usb/gadget/function/f_mass_storage.c | 21 ++++++++++++++------ > drivers/usb/gadget/function/storage_common.h | 1 + > 2 files changed, 16 insertions(+), 6 deletions(-) > > diff --git a/drivers/usb/gadget/function/f_mass_storage.c b/drivers/usb/gadget/function/f_mass_storage.c > index 043f97ad8f22..982c3e89eb0d 100644 > --- a/drivers/usb/gadget/function/f_mass_storage.c > +++ b/drivers/usb/gadget/function/f_mass_storage.c > This patch may have issue. It was reverted upstream. Please don't queue to stable. BR, Thinh
