usb: chipidea: udc: fix NULL ptr dereference in isr_setup_status_phase

Problems with the signal integrity of the high speed USB data lines or
noise on reference ground lines can cause the i.MX6 USB controller to
violate USB specs and exhibit unexpected behavior.

It was observed that USBi_UI interrupts were triggered first and when
isr_setup_status_phase was called, ci->status was NULL, which lead to a
NULL pointer dereference kernel panic.

This patch fixes the kernel panic, emits a warning once and returns
-EPIPE to halt the device and let the host get stalled.
It also adds a comment to point people, who are experiencing this issue,
to their USB hardware design.

Cc: <stable@vger.kernel.org> #4.1+
Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>

path: root/epoll2.h

#ifndef __EPOLL_H
#define __EPOLL_H

extern void set_epoll_descriptor(int fd_epoll, int action, int fd_toadd, int events);
extern int set_epoll_descriptor2(int fd_epoll, int action, int fd_toadd, int events);

#endif /* __EPOLL_H */