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authorChris Wilson <chris@chris-wilson.co.uk>2011-03-23 18:16:55 +0000
committerLinus Torvalds <torvalds@linux-foundation.org>2011-03-23 19:45:06 -0700
commit968b503e69a6b90aa4a3b9162960f605b6abd821 (patch)
treeb11144867500373dc33b1d85413dbf575e849c90
parent4bbba111d94781d34081c37856bbc5eb33f6c72a (diff)
Revert "drm/i915: Don't save/restore hardware status page address register"
This reverts commit a7a75c8f70d6f6a2f16c9f627f938bbee2d32718. There are two different variations on how Intel hardware addresses the "Hardware Status Page". One as a location in physical memory and the other as an offset into the virtual memory of the GPU, used in more recent chipsets. (The HWS itself is a cacheable region of memory which the GPU can write to without requiring CPU synchronisation, used for updating various details of hardware state, such as the position of the GPU head in the ringbuffer, the last breadcrumb seqno, etc). These two types of addresses were updated in different locations of code - one inline with the ringbuffer initialisation, and the other during device initialisation. (The HWS page is logically associated with the rings, and there is one HWS page per ring.) During resume, only the ringbuffers were being re-initialised along with the virtual HWS page, leaving the older physical address HWS untouched. This then caused a hang on the older gen3/4 (915GM, 945GM, 965GM) the first time we tried to synchronise the GPU as the breadcrumbs were never being updated. Reported-and-tested-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Jan Niehusmann <jan@gondor.com> Reported-by: Justin P. Mattock <justinmattock@gmail.com> Reported-and-tested-by: Michael "brot" Groh <brot@minad.de> Cc: Zhenyu Wang <zhenyuw@linux.intel.com> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/gpu/drm/i915/i915_drv.h1
-rw-r--r--drivers/gpu/drm/i915/i915_suspend.c6
2 files changed, 7 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 449650545bb4..5004724ea57e 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -383,6 +383,7 @@ typedef struct drm_i915_private {
u32 saveDSPACNTR;
u32 saveDSPBCNTR;
u32 saveDSPARB;
+ u32 saveHWS;
u32 savePIPEACONF;
u32 savePIPEBCONF;
u32 savePIPEASRC;
diff --git a/drivers/gpu/drm/i915/i915_suspend.c b/drivers/gpu/drm/i915/i915_suspend.c
index 7e992a8e9098..da474153a0a2 100644
--- a/drivers/gpu/drm/i915/i915_suspend.c
+++ b/drivers/gpu/drm/i915/i915_suspend.c
@@ -796,6 +796,9 @@ int i915_save_state(struct drm_device *dev)
pci_read_config_byte(dev->pdev, LBB, &dev_priv->saveLBB);
+ /* Hardware status page */
+ dev_priv->saveHWS = I915_READ(HWS_PGA);
+
i915_save_display(dev);
/* Interrupt state */
@@ -842,6 +845,9 @@ int i915_restore_state(struct drm_device *dev)
pci_write_config_byte(dev->pdev, LBB, dev_priv->saveLBB);
+ /* Hardware status page */
+ I915_WRITE(HWS_PGA, dev_priv->saveHWS);
+
i915_restore_display(dev);
/* Interrupt state */