Re: [PATCH] drm/i915: setup workarounds on reset

[Mika Kuoppala <mika.kuoppala@linux.intel.com>]

Daniel Vetter <daniel@ffwll.ch> writes:

Hi Daniel,

> On Mon, Nov 18, 2013 at 04:34:44PM +0200, Mika Kuoppala wrote:
>> Large parts of hw initialization is behind per gen
>> clock gating functions. Including workarounds.
>> 
>> Call intel_modeset_init_hw after reset so that we
>> set these up correctly.
>> 
>> Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
>> ---
>>  drivers/gpu/drm/i915/i915_drv.c |    2 ++
>>  1 file changed, 2 insertions(+)
>> 
>> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
>> index c2e00ed..2908f7f 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.c
>> +++ b/drivers/gpu/drm/i915/i915_drv.c
>> @@ -798,6 +798,8 @@ int i915_reset(struct drm_device *dev)
>>  		drm_irq_uninstall(dev);
>>  		drm_irq_install(dev);
>>  		intel_hpd_init(dev);
>> +
>> +		intel_modeset_init_hw(dev);
>
> Currently the idea is that w/as which get nuked by the gt reset should be
> put into the respective ring_init function in intel_ringbuffer.c. This
> disdinction is important since init_clock_gating gets called fairly early
> in the resume/load sequence before most of the gem stuff is set up. And
> the w/a in the ring_init functions are carefully ordered wrt the ring (re)
> enabling.
>
> So which bit/register is the culprit here?

Here is output from the test on ivb, after drv_hangman:

FAIL     WaDisableEarlyCull:ivb
OK       WaDisableBackToBackFlipFix:ivb
FAIL     WaDisablePSDDualDispatchEnable:ivb
FAIL     WaDisableRHWOptimizationForRenderHang:ivb
FAIL     WaApplyL3ControlAndL3ChickenMode:ivb
OK       WaForceL3Serialization:ivb
OK       WaDisableRCZUnitClockGating:ivb
OK       WaCatErrorRejectionIssue:ivb
FAIL     WaVSRefCountFullforceMissDisable:ivb
FAIL     WaDisable4x2SubspanOptimization:ivb
10 workarounds tested, 4 passed, 6 failed
Test assertion failure function main, file drv_workarounds.c:119:
Failed assertion: check_workarounds(&ivb_workarounds[0], "ivb") == 0

Test can be found in here:
https://github.com/mkuoppal/intel-gpu-tools/tree/was

-Mika