Hi Sasha,
Sasha Levin wrote:
From: EJ Hsu ejh@nvidia.com
[ 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@rowland.harvard.edu Signed-off-by: EJ Hsu ejh@nvidia.com Signed-off-by: Felipe Balbi felipe.balbi@linux.intel.com Signed-off-by: Sasha Levin sashal@kernel.org
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