drm/i915: disable IPS while getting the pipe CRCs.
Subsystems (2)
PATCH 1/1 drm/i915: disable IPS while getting the pipe CRCs.
From: Paulo Zanoni <[email protected]>
For some yet-undiscovered reason, when IPS gets enabled, the pipe CRC changes. Since hsw_enable_ips() doesn't really guarantees to enable IPS (it depends on package C-states), we can't really predict if IPS is enabled or disabled while running our CRC tests, so let's just completely disable IPS while pipe CRCs are being used.
If we find a way to make IPS not change the pipe CRC result, we may want to fix IPS and then revert this patch. While this doesn't happen, let's merge this patch, so every IGT test relying on the CRCs can work on pipe A.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=72864
Testcase: igt/kms_cursor_crc (and others)
--- drivers/gpu/drm/i915/i915_debugfs.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
drivers/gpu/drm/i915/i915_debugfs.c +12 -0
@@ -3255,6 +3255,8 @@ static int pipe_crc_set_source(struct drm_device *dev, enum pipe pipe, {struct drm_i915_private *dev_priv = dev->dev_private;struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[pipe]; +struct intel_crtc *crtc =to_intel_crtc (intel_get_crtc_for_pipe (dev, + pipe));u32 val =0 ;/* shut up gcc */ int ret;
@@ -3290,6 +3292,14 @@ static int pipe_crc_set_source(struct drm_device *dev, enum pipe pipe,if (!pipe_crc->entries)return -ENOMEM ; +/* +* When IPS gets enabled, the pipe CRC changes. Since IPS gets +* enabled and disabled dynamically based on package C states, +* user space can't make reliable use of the CRCs, so let's just +* completely disable it. +*/ +hsw_disable_ips (crtc); +spin_lock_irq (&pipe_crc->lock); pipe_crc->head =0 ; pipe_crc->tail =0 ;
@@ -3328,6 +3338,8 @@ static int pipe_crc_set_source(struct drm_device *dev, enum pipe pipe,vlv_undo_pipe_scramble_reset (dev, pipe); else if (IS_HASWELL(dev) && pipe == PIPE_A) hsw_undo_trans_edp_pipe_A_crc_wa(dev); + +hsw_enable_ips (crtc ); }return 0 ;
Signature · 1 line
2.1.1
Quoted 8 lines · Paulo Zanoni
From: Paulo Zanoni <[email protected]>
For some yet-undiscovered reason, when IPS gets enabled, the pipe CRC changes. Since
hsw_enable_ips()doesn't really guarantees to enable IPS (it depends on package C-states), we can't really predict if IPS is enabled or disabled while running our CRC tests, so let's just completely disable IPS while pipe CRCs are being used.
Quoted 8 lines
If we find a way to make IPS not change the pipe CRC result, we may want to fix IPS and then revert this patch. While this doesn't happen, let's merge this patch, so every IGT test relying on the CRCs can work on pipe A.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=72864
Testcase: igt/kms_cursor_crc (and others)Signed-off-by Paulo Zanoni <[email protected]>
Apparently we don't yet fully understand what's going on. But while the hw ppl chase this, let's make the testcases work again. I think your little hack here is a bit too ugly though, especially in the brave new world where we have atomic updates. I'm thinking of something similar like we have for the hsw pfit wa. We'd need that for the sprite ips workaround that we have already too.
But that flag should be in the plane config, so right now we can't really do that. So I've merged your patch as a stopgap.
Thanks, Daniel
Quoted 48 lines
--- drivers/gpu/drm/i915/i915_debugfs.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)drivers/gpu/drm/i915/i915_debugfs.c +12
-0@@ -3255,6 +3255,8 @@ static int pipe_crc_set_source(struct drm_device *dev, enum pipe pipe, {struct drm_i915_private *dev_priv = dev->dev_private;struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[pipe]; +struct intel_crtc *crtc =to_intel_crtc (intel_get_crtc_for_pipe (dev, + pipe));u32 val =0 ;/* shut up gcc */ int ret;@@ -3290,6 +3292,14 @@ static int pipe_crc_set_source(struct drm_device *dev, enum pipe pipe,if (!pipe_crc->entries)return -ENOMEM ; +/* +* When IPS gets enabled, the pipe CRC changes. Since IPS gets +* enabled and disabled dynamically based on package C states, +* user space can't make reliable use of the CRCs, so let's just +* completely disable it. +*/ +hsw_disable_ips (crtc); +spin_lock_irq (&pipe_crc->lock); pipe_crc->head =0 ; pipe_crc->tail =0 ;@@ -3328,6 +3338,8 @@ static int pipe_crc_set_source(struct drm_device *dev, enum pipe pipe,vlv_undo_pipe_scramble_reset (dev, pipe); else if (IS_HASWELL(dev) && pipe == PIPE_A) hsw_undo_trans_edp_pipe_A_crc_wa(dev); + +hsw_enable_ips (crtc ); }return 0 ;Signature · 6 lines
2.1.1 _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
Signature · 3 lines
Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch