tracing: Fix hwlat kthread migration

The hwlat tracer creates a kernel thread at start of the tracer. It is
pinned to a single CPU and will move to the next CPU after each period of
running. If the user modifies the migration thread's affinity, it will not
change after that happens.

The original code created the thread at the first instance it was called,
but later was changed to destroy the thread after the tracer was finished,
and would not be created until the next instance of the tracer was
established. The code that initialized the affinity was only called on the
initial instantiation of the tracer. After that, it was not initialized, and
the previous affinity did not match the current newly created one, making
it appear that the user modified the thread's affinity when it did not, and
the thread failed to migrate again.

Cc: stable@vger.kernel.org
Fixes: 0330f7aa8ee6 ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

path: root/include/soc/at91/atmel-sfr.h

/*
 * Atmel SFR (Special Function Registers) register offsets and bit definitions.
 *
 * Copyright (C) 2016 Atmel
 *
 * Author: Ludovic Desroches <ludovic.desroches@atmel.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#ifndef _LINUX_MFD_SYSCON_ATMEL_SFR_H
#define _LINUX_MFD_SYSCON_ATMEL_SFR_H

#define AT91_SFR_DDRCFG		0x04	/* DDR Configuration Register */
/* 0x08 ~ 0x0c: Reserved */
#define AT91_SFR_OHCIICR	0x10	/* OHCI INT Configuration Register */
#define AT91_SFR_OHCIISR	0x14	/* OHCI INT Status Register */
#define AT91_SFR_I2SCLKSEL	0x90	/* I2SC Register */

/* Field definitions */
#define AT91_OHCIICR_SUSPEND_A	BIT(8)
#define AT91_OHCIICR_SUSPEND_B	BIT(9)
#define AT91_OHCIICR_SUSPEND_C	BIT(10)

#define AT91_OHCIICR_USB_SUSPEND	(AT91_OHCIICR_SUSPEND_A | \
					 AT91_OHCIICR_SUSPEND_B | \
					 AT91_OHCIICR_SUSPEND_C)


#endif /* _LINUX_MFD_SYSCON_ATMEL_SFR_H */