radeonfb: Whack the PCI PM register until it sticks
This fixes a regression introduced when we switched to using the core
pci_set_power_state(). The chip seems to need the state to be written
over and over again until it sticks, so we do that.
Note that the code is a bit blunt, without timeout, etc... but that's
pretty much because I put back in there the code exactly as it used to
be before the regression. I still add a call to pci_set_power_state()
at the end so that ACPI gets called appropriately on x86.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Raymond Wooninck <tittiatcoke@gmail.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/video/aty/radeon_pm.c b/drivers/video/aty/radeon_pm.c
index 81603f8..c6d7cc7 100644
--- a/drivers/video/aty/radeon_pm.c
+++ b/drivers/video/aty/radeon_pm.c
@@ -2507,6 +2507,25 @@
#endif /* CONFIG_PPC_OF */
+static void radeonfb_whack_power_state(struct radeonfb_info *rinfo, pci_power_t state)
+{
+ u16 pwr_cmd;
+
+ for (;;) {
+ pci_read_config_word(rinfo->pdev,
+ rinfo->pm_reg+PCI_PM_CTRL,
+ &pwr_cmd);
+ if (pwr_cmd & 2)
+ break;
+ pwr_cmd = (pwr_cmd & ~PCI_PM_CTRL_STATE_MASK) | 2;
+ pci_write_config_word(rinfo->pdev,
+ rinfo->pm_reg+PCI_PM_CTRL,
+ pwr_cmd);
+ msleep(500);
+ }
+ rinfo->pdev->current_state = state;
+}
+
static void radeon_set_suspend(struct radeonfb_info *rinfo, int suspend)
{
u32 tmp;
@@ -2558,6 +2577,11 @@
/* Switch PCI power management to D2. */
pci_disable_device(rinfo->pdev);
pci_save_state(rinfo->pdev);
+ /* The chip seems to need us to whack the PM register
+ * repeatedly until it sticks. We do that -prior- to
+ * calling pci_set_power_state()
+ */
+ radeonfb_whack_power_state(rinfo, PCI_D2);
pci_set_power_state(rinfo->pdev, PCI_D2);
} else {
printk(KERN_DEBUG "radeonfb (%s): switching to D0 state...\n",