From: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx>
Our driver initialization doesn't seem to be ready to load when the
power well is disabled: we hit a few "Unclaimed register" messages. So
do just like we already do for the suspend/resume path: enable the
power well before unloading.
At some point we'll want to be able to survive suspend/resume and
load/unload with the power well disabled, but for now let's just fix
the regression.
Regression introduced by the following commit:
commit bf51d5e2cda5d36d98e4b46ac7fca9461e512c41
Author: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx>
Date: Wed Jul 3 17:12:13 2013 -0300
drm/i915: switch disable_power_well default value to 1
Bug can be reproduced by running the "module_reload" script from
intel-gpu-tools.
Cc: stable@xxxxxxxxxxxxxxx
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=67813
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx>
---
drivers/gpu/drm/i915/i915_dma.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
QA (the bug reporter) still didn't confirm this patch fixes the bug, but I can
reproduce it and I can confirm it fixes the problem at least on my machine.
Also please notice we have other problems that happen when we run module_reload
(e.g., gpu hang, no backlight, lockdep error message, eventual oops), this patch
fixes only the "Unclaimed register" errors.
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index b30404d..d2dc02b 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1688,8 +1688,13 @@ int i915_driver_unload(struct drm_device *dev)
intel_gpu_ips_teardown();
- if (HAS_POWER_WELL(dev))
+ if (HAS_POWER_WELL(dev)) {
+ /* The i915.ko module is still not prepared to be loaded when
+ * the power well is not enabled, so just enable it in case
+ * we're going to unload/reload. */
+ intel_set_power_well(dev, true);
i915_remove_power_well(dev);
+ }
i915_teardown_sysfs(dev);
--
1.8.1.2
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