Revision a01cc6570326c01e70619bf6540fb32139947c33 authored by David Brownell on 04 July 2008, 16:59:26 UTC, committed by Linus Torvalds on 04 July 2008, 17:40:04 UTC
While 0e36a9a4a788e4e92407774df76c545910810d35 ("rtc: fix readback from
/sys/class/rtc/rtc?/wakealarm") made sure that active alarms were never
returned with invalid "wildcard" fields (negative), it can still report
(wrongly) that the alarm triggers in the past.

Example, if it's now 10am, an alarm firing at 5am will be triggered
TOMORROW not today.  (Which may also be next month or next year...)

This updates that alarm handling in three ways:

  * Handle alarm rollover in the common cases of RTCs that don't
    support matching on all date fields.

  * Skip the invalid-field logic when it's not needed.

  * Minor bugfix ... tm_isdst should be ignored, it's one of the
    fields Linux doesn't maintain.

A warning is emitted for some of the unhandled rollover cases, but the
possible combinations are a bit too numerous to handle every bit of
potential hardware and firmware braindamage.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Mark Lord <lkml@rtr.ca>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 251b97f
Raw File
iomap_copy.c
/*
 * Copyright 2006 PathScale, Inc.  All Rights Reserved.
 *
 * This file is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#include <linux/module.h>
#include <linux/io.h>

/**
 * __iowrite32_copy - copy data to MMIO space, in 32-bit units
 * @to: destination, in MMIO space (must be 32-bit aligned)
 * @from: source (must be 32-bit aligned)
 * @count: number of 32-bit quantities to copy
 *
 * Copy data from kernel space to MMIO space, in units of 32 bits at a
 * time.  Order of access is not guaranteed, nor is a memory barrier
 * performed afterwards.
 */
void __attribute__((weak)) __iowrite32_copy(void __iomem *to,
					    const void *from,
					    size_t count)
{
	u32 __iomem *dst = to;
	const u32 *src = from;
	const u32 *end = src + count;

	while (src < end)
		__raw_writel(*src++, dst++);
}
EXPORT_SYMBOL_GPL(__iowrite32_copy);

/**
 * __iowrite64_copy - copy data to MMIO space, in 64-bit or 32-bit units
 * @to: destination, in MMIO space (must be 64-bit aligned)
 * @from: source (must be 64-bit aligned)
 * @count: number of 64-bit quantities to copy
 *
 * Copy data from kernel space to MMIO space, in units of 32 or 64 bits at a
 * time.  Order of access is not guaranteed, nor is a memory barrier
 * performed afterwards.
 */
void __attribute__((weak)) __iowrite64_copy(void __iomem *to,
					    const void *from,
					    size_t count)
{
#ifdef CONFIG_64BIT
	u64 __iomem *dst = to;
	const u64 *src = from;
	const u64 *end = src + count;

	while (src < end)
		__raw_writeq(*src++, dst++);
#else
	__iowrite32_copy(to, from, count * 2);
#endif
}

EXPORT_SYMBOL_GPL(__iowrite64_copy);
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