b43: avoid PPC fault during resume

b43: avoid PPC fault during resume

commit c2ff581acab16c6af56d9e8c1a579bf041ec00b1 upstream.

The routine b43_is_hw_radio_enabled() has long been a problem.
For PPC architecture with PHY Revision < 3, a read of the register
B43_MMIO_HWENABLED_LO will cause a CPU fault unless b43_status()
returns a value of 2 (B43_STAT_STARTED) (BUG 14181). Fixing that
results in Bug 14538 in which the driver is unable to reassociate
after resuming from hibernation because b43_status() returns 0.

The correct fix would be to determine why the status is 0; however,
I have not yet found why that happens. The correct value is found for
my device, which has PHY revision >= 3.

Returning TRUE when the PHY revision < 3 and b43_status() returns 0 fixes
the regression for 2.6.32.

This patch fixes the problem in Red Hat Bugzilla #538523.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Tested-by: Christian Casteyde <casteyde.christian@free.fr>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>