From: Abhay Kumar abhay.kumar@intel.com
In GLK when the device boots with only 1366x768 panel without audio, HDA codec doesn't come up. In this case, the CDCLK is less than twice the BCLK. Even though audio isn't being enabled, having a too low CDCLK leads to audio probe failing altogether.
Require CDCLK to be at least twice the BLCK regardless of audio. This is a minimal fix to improve things. Unfortunately, this a) leads to too high CDCLK being used when audio is not used, and b) is still not enough to fix audio probe when no outputs are connected at probe time.
The proper fix would be to increase CDCLK dynamically from the audio component hooks.
v2: - Address comment (Jani) - New design approach v3: - Typo fix on top of v1
v4 by Jani: rewrite commit message, add comment in code
Cc: stable@vger.kernel.org Cc: Ville Syrjälä ville.syrjala@linux.intel.com Cc: Dhinakaran Pandiyan dhinakaran.pandiyan@gmail.com Cc: Wenkai Du wenkai.du@intel.com Reviewed-by: Wenkai Du wenkai.du@intel.com Tested-by: Wenkai Du wenkai.du@intel.com Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=102937 Signed-off-by: Abhay Kumar abhay.kumar@intel.com Signed-off-by: Jani Nikula jani.nikula@intel.com --- drivers/gpu/drm/i915/intel_cdclk.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_cdclk.c b/drivers/gpu/drm/i915/intel_cdclk.c index fc8b2c6e3508..32d24c69da3c 100644 --- a/drivers/gpu/drm/i915/intel_cdclk.c +++ b/drivers/gpu/drm/i915/intel_cdclk.c @@ -2140,10 +2140,22 @@ int intel_crtc_compute_min_cdclk(const struct intel_crtc_state *crtc_state) } }
- /* According to BSpec, "The CD clock frequency must be at least twice + /* + * According to BSpec, "The CD clock frequency must be at least twice * the frequency of the Azalia BCLK." and BCLK is 96 MHz by default. + * + * FIXME: Check the actual, not default, BCLK being used. + * + * FIXME: This does not depend on ->has_audio because the higher CDCLK + * is required for audio probe, also when there are no audio capable + * displays connected at probe time. This leads to unnecessarily high + * CDCLK when audio is not required. + * + * FIXME: This limit is only applied when there are displays connected + * at probe time. If we probe without displays, we'll still end up using + * the platform minimum CDCLK, failing audio probe. */ - if (crtc_state->has_audio && INTEL_GEN(dev_priv) >= 9) + if (INTEL_GEN(dev_priv) >= 9) min_cdclk = max(2 * 96000, min_cdclk);
/*