From: Benjamin Herrenschmidt Date: Thu, 19 Mar 2009 22:22:30 +0000 (+1100) Subject: radeonfb: Whack the PCI PM register until it sticks X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=18a0d89e54ca0f6f33582f99ae39867b2c975559;p=linux-2.6-omap-h63xx.git 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 Tested-by: Raymond Wooninck Acked-by: Rafael J. Wysocki Cc: Jesse Barnes Cc: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/video/aty/radeon_pm.c b/drivers/video/aty/radeon_pm.c index 81603f85e17..c6d7cc76516 100644 --- a/drivers/video/aty/radeon_pm.c +++ b/drivers/video/aty/radeon_pm.c @@ -2507,6 +2507,25 @@ static void radeon_reinitialize_QW(struct radeonfb_info *rinfo) #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 @@ static void radeon_set_suspend(struct radeonfb_info *rinfo, int suspend) /* 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",