Revision 883a649b737cdbe3ede7e50f3f939fd706ed5c4e authored by Stanislaw Gruszka on 13 March 2012, 15:11:27 UTC, committed by John W. Linville on 26 March 2012, 19:07:22 UTC
This il->vif is dereferenced in different part of iwlegacy code, so do
not nullify it. This should fix random crashes observed in companion
with microcode errors i.e. crash in il3945_config_ap().

Additionally this should address also
WARNING: at drivers/net/wireless/iwlegacy/common.c:4656 il_mac_remove_interface
at least one of the possible reasons of that warning.

Cc: stable@vger.kernel.org
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
1 parent 8a78335
Raw File
average.c
/*
 * lib/average.c
 *
 * This source code is licensed under the GNU General Public License,
 * Version 2.  See the file COPYING for more details.
 */

#include <linux/module.h>
#include <linux/average.h>
#include <linux/bug.h>
#include <linux/log2.h>

/**
 * DOC: Exponentially Weighted Moving Average (EWMA)
 *
 * These are generic functions for calculating Exponentially Weighted Moving
 * Averages (EWMA). We keep a structure with the EWMA parameters and a scaled
 * up internal representation of the average value to prevent rounding errors.
 * The factor for scaling up and the exponential weight (or decay rate) have to
 * be specified thru the init fuction. The structure should not be accessed
 * directly but only thru the helper functions.
 */

/**
 * ewma_init() - Initialize EWMA parameters
 * @avg: Average structure
 * @factor: Factor to use for the scaled up internal value. The maximum value
 *	of averages can be ULONG_MAX/(factor*weight). For performance reasons
 *	factor has to be a power of 2.
 * @weight: Exponential weight, or decay rate. This defines how fast the
 *	influence of older values decreases. For performance reasons weight has
 *	to be a power of 2.
 *
 * Initialize the EWMA parameters for a given struct ewma @avg.
 */
void ewma_init(struct ewma *avg, unsigned long factor, unsigned long weight)
{
	WARN_ON(!is_power_of_2(weight) || !is_power_of_2(factor));

	avg->weight = ilog2(weight);
	avg->factor = ilog2(factor);
	avg->internal = 0;
}
EXPORT_SYMBOL(ewma_init);

/**
 * ewma_add() - Exponentially weighted moving average (EWMA)
 * @avg: Average structure
 * @val: Current value
 *
 * Add a sample to the average.
 */
struct ewma *ewma_add(struct ewma *avg, unsigned long val)
{
	avg->internal = avg->internal  ?
		(((avg->internal << avg->weight) - avg->internal) +
			(val << avg->factor)) >> avg->weight :
		(val << avg->factor);
	return avg;
}
EXPORT_SYMBOL(ewma_add);
back to top