• P
    drm/i915: disable IPS while getting the sink CRCs · 4373f0f2
    Paulo Zanoni 提交于
    This commit is the "sink CRC" version of:
    
    commit 8c740dce
    Author: Paulo Zanoni <paulo.r.zanoni@intel.com>
    Date:   Fri Oct 17 18:42:03 2014 -0300
        drm/i915: disable IPS while getting the pipe CRCs.
    
    For some unknown reason, when IPS gets enabled, the sink CRC changes.
    Since hsw_enable_ips() doesn't really guarantee 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 sink 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 (and 8c740dce too). While
    this doesn't happen, let's merge this patch, so the IGT tests relying
    on sink CRCs can work properly.
    
    This was discovered while developing a new IGT test, which will
    probably be called kms_frontbuffer_tracking.
    
    Testcase: igt/kms_frontbuffer_tracking (not on upstream IGT yet)
    Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
    Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
    Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
    Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
    4373f0f2
intel_dp.c 167.8 KB