linux/drivers/net/wireless/b43legacy/rfkill.c
Larry Finger 316a4d966c b43legacy: avoid PPC fault during resume
For PPC architecture with PHY Revision < 3, a read of the register
B43_MMIO_HWENABLED_LO will cause a CPU fault unless b43legacy_status()
returns a value of 2 (B43legacy_STAT_STARTED); however, one finds that
the driver is unable to associate after resuming from hibernation unless
this routine returns 1. To satisfy both conditions, the routine is rewritten
to return TRUE whenever b43legacy_status() returns a value < 2.

This patch fixes the second problem listed in the postings for Red Hat
Bugzilla #538523.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Stable <stable@vger.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-12-04 13:28:50 -05:00

92 lines
2.6 KiB
C

/*
Broadcom B43 wireless driver
RFKILL support
Copyright (c) 2007 Michael Buesch <mb@bu3sch.de>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
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; see the file COPYING. If not, write to
the Free Software Foundation, Inc., 51 Franklin Steet, Fifth Floor,
Boston, MA 02110-1301, USA.
*/
#include "radio.h"
#include "b43legacy.h"
/* Returns TRUE, if the radio is enabled in hardware. */
bool b43legacy_is_hw_radio_enabled(struct b43legacy_wldev *dev)
{
if (dev->phy.rev >= 3) {
if (!(b43legacy_read32(dev, B43legacy_MMIO_RADIO_HWENABLED_HI)
& B43legacy_MMIO_RADIO_HWENABLED_HI_MASK))
return 1;
} else {
/* To prevent CPU fault on PPC, do not read a register
* unless the interface is started; however, on resume
* for hibernation, this routine is entered early. When
* that happens, unconditionally return TRUE.
*/
if (b43legacy_status(dev) < B43legacy_STAT_STARTED)
return 1;
if (b43legacy_read16(dev, B43legacy_MMIO_RADIO_HWENABLED_LO)
& B43legacy_MMIO_RADIO_HWENABLED_LO_MASK)
return 1;
}
return 0;
}
/* The poll callback for the hardware button. */
void b43legacy_rfkill_poll(struct ieee80211_hw *hw)
{
struct b43legacy_wl *wl = hw_to_b43legacy_wl(hw);
struct b43legacy_wldev *dev = wl->current_dev;
struct ssb_bus *bus = dev->dev->bus;
bool enabled;
bool brought_up = false;
mutex_lock(&wl->mutex);
if (unlikely(b43legacy_status(dev) < B43legacy_STAT_INITIALIZED)) {
if (ssb_bus_powerup(bus, 0)) {
mutex_unlock(&wl->mutex);
return;
}
ssb_device_enable(dev->dev, 0);
brought_up = true;
}
enabled = b43legacy_is_hw_radio_enabled(dev);
if (unlikely(enabled != dev->radio_hw_enable)) {
dev->radio_hw_enable = enabled;
b43legacyinfo(wl, "Radio hardware status changed to %s\n",
enabled ? "ENABLED" : "DISABLED");
wiphy_rfkill_set_hw_state(hw->wiphy, !enabled);
if (enabled != dev->phy.radio_on) {
if (enabled)
b43legacy_radio_turn_on(dev);
else
b43legacy_radio_turn_off(dev, 0);
}
}
if (brought_up) {
ssb_device_disable(dev->dev, 0);
ssb_bus_may_powerdown(bus);
}
mutex_unlock(&wl->mutex);
}