PCI PM: Follow PCI_PM_CTRL_NO_SOFT_RESET during transitions from D3
authorRafael J. Wysocki <rjw@sisk.pl>
Mon, 18 May 2009 20:51:12 +0000 (22:51 +0200)
committerJesse Barnes <jbarnes@virtuousgeek.org>
Thu, 11 Jun 2009 19:04:20 +0000 (12:04 -0700)
commitf62795f1e892ca9269849fa83de97621da7e02c0
treecfa28abc0ec45270045e7fd0e852efd1e3e319a3
parent4d135dbee7b0a89e946f7ba284f2b957505a2c3a
PCI PM: Follow PCI_PM_CTRL_NO_SOFT_RESET during transitions from D3

According to the PCI PM specification (PCI Bus Power Management
Interface Specification, Rev. 1.2, Section 5.4.1) we are supposed to
reinitialize devices that have PCI_PM_CTRL_NO_SOFT_RESET clear during
all transitions from PCI_D3hot to PCI_D0, but we only do it if the
device's current_state field is equal to PCI_UNKNOWN.

This may lead to problems if a device with PCI_PM_CTRL_NO_SOFT_RESET
unset is put into PCI_D3hot at run time by its driver and
pci_set_power_state() is used to put it back into PCI_D0, because in
that case the device will remain uninitialized after
pci_set_power_state() has returned.  Prevent that from happening by
modifying pci_raw_set_power_state() to reinitialize devices with
PCI_PM_CTRL_NO_SOFT_RESET unset during all transitions from D3 to D0.

Cc: stable@kernel.org
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
drivers/pci/pci.c