linux_dsm_epyc7002/drivers/usb/gadget
Michal Nazarewicz f78bbcae86 usb: f_mass_storage: test whether thread is running before starting another
When binding the function to usb_configuration, check whether the thread
is running before starting another one.  Without that, when function
instance is added to multiple configurations, fsg_bing starts multiple
threads with all but the latest one being forgotten by the driver.  This
leads to obvious thread leaks, possible lockups when trying to halt the
machine and possible more issues.

This fixes issues with legacy/multi¹ gadget as well as configfs gadgets
when mass_storage function is added to multiple configurations.

This change also simplifies API since the legacy gadgets no longer need
to worry about starting the thread by themselves (which was where bug
in legacy/multi was in the first place).

N.B., this patch doesn’t address adding single mass_storage function
instance to a single configuration twice.  Thankfully, there’s no
legitimate reason for such setup plus, if I’m not mistaken, configfs
gadget doesn’t even allow it to be expressed.

¹ I have no example failure though.  Conclusion that legacy/multi has
  a bug is based purely on me reading the code.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Tested-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: <stable@vger.kernel.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-04-19 11:11:56 +03:00
..
function usb: f_mass_storage: test whether thread is running before starting another 2016-04-19 11:11:56 +03:00
legacy usb: f_mass_storage: test whether thread is running before starting another 2016-04-19 11:11:56 +03:00
udc usb: gadget: r8a66597-udc: Deinline pipe_change, save 2176 bytes 2016-04-19 11:11:55 +03:00
composite.c usb: gadget: composite: Access SSP Dev Cap fields properly 2016-03-29 13:25:57 +03:00
config.c usb: gadget: Update function for SuperSpeedPlus 2016-03-04 15:14:23 +02:00
configfs.c Configfs changes for the 4.6 merge window: 2016-03-17 16:25:46 -07:00
configfs.h usb: gadget: OS descriptors: provide interface directory names 2014-06-19 10:06:48 -05:00
epautoconf.c usb: gadget: epautoconf: add usb_ep_autoconfig_release() function 2015-09-27 10:54:31 -05:00
functions.c
Kconfig usb: common: rework CONFIG_USB_COMMON logic 2016-04-18 15:23:36 +03:00
Makefile usb: gadget: use $(srctree) instead of $(PWD) for includes 2014-08-29 15:53:46 -05:00
u_f.c usb: gadget: define free_ep_req as universal function 2015-12-15 09:12:41 -06:00
u_f.h usb: gadget: define free_ep_req as universal function 2015-12-15 09:12:41 -06:00
u_os_desc.h usb: gadget: u_os_desc: helper functions for accessing ext prop buffer 2014-07-10 08:36:51 -05:00
usbstring.c usb: delete non-required instances of include <linux/init.h> 2014-01-08 15:01:39 -08:00