Re: [resend] i915: high power consumption after suspend/resume

From: Andrew Lutomirski
Date: Tue Nov 10 2009 - 09:43:01 EST


Just to confuse matters further, the following patch does *not* help.
Even with this patch applied, power consumption often goes high when
resuming, and writing 1 to i915_wedged after fully resuming fixes it.

I now officially have no clue what's going on. Maybe there's
something wrong with the i915 resume code that increases power
consumption.

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 7f436ec..71472a9 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -99,11 +99,28 @@ static int i915_resume(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
int ret = 0;
+ u8 gdrst;
+ unsigned long timeout;
+

if (pci_enable_device(dev->pdev))
return -1;
pci_set_master(dev->pdev);

+ pci_read_config_byte(dev->pdev, GDRST, &gdrst);
+ pci_write_config_byte(dev->pdev, GDRST, gdrst | GDRST_RENDER);
+ udelay(50);
+ //pci_write_config_byte(dev->pdev, GDRST, gdrst & 0xfe);
+
+ /* ...we don't want to loop forever though, 500ms should be plenty */
+ timeout = jiffies + msecs_to_jiffies(500);
+ do {
+ udelay(100);
+ pci_read_config_byte(dev->pdev, GDRST, &gdrst);
+ } while ((gdrst & 0x1) && time_after(timeout, jiffies));
+ printk(KERN_INFO "i915: Reset on resume took %d ms\n",
+ jiffies_to_msecs(jiffies - timeout + msecs_to_jiffies(500)));
+
i915_restore_state(dev);

intel_opregion_init(dev, 1);

--Andy
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