Toggle the Software Clear Interrupt bit which resets the controller to clear any prior BUS_ERROR condition before we begin to use the controller in earnest.
Suggested-by: Ben Widawsky <[email protected]> Signed-off-by: Chris Wilson <[email protected]> --- drivers/gpu/drm/i915/intel_i2c.c | 12 ++++++++---- 1 files changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c index ed11523..bf1c72c 100644 --- a/drivers/gpu/drm/i915/intel_i2c.c +++ b/drivers/gpu/drm/i915/intel_i2c.c @@ -60,10 +60,14 @@ void intel_i2c_reset(struct drm_device *dev) { struct drm_i915_private *dev_priv = dev->dev_private; - if (HAS_PCH_SPLIT(dev)) - I915_WRITE(PCH_GMBUS0, 0); - else - I915_WRITE(GMBUS0, 0); + int reg = intel_gmbus_reg0(dev); + + /* First reset the controller by toggling the Sw Clear Interrupt. */ + I915_WRITE(reg + 1, GMBUS_SW_CLR_INT); + I915_WRITE(reg + 1, 0); + + /* Then mark the controller as disabled. */ + I915_WRITE(reg + 0, 0); } static void intel_i2c_quirk_set(struct drm_i915_private *dev_priv, bool enable) -- 1.7.5.1 _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
