Messages in this thread Patch in this message | | | From | Daniel Kurtz <> | Subject | [PATCH 11/11 v3] drm/i915/intel_i2c: reuse GMBUS2 value read in polling loop | Date | Mon, 26 Mar 2012 22:26:50 +0800 |
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Save the GMBUS2 value read while polling for state changes, and then reuse this value when determining for which reason the loops were exited. This is a small optimization which saves a couple of bus accesses for memory mapped IO registers.
Signed-off-by: Daniel Kurtz <djkurtz@chromium.org> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> --- drivers/gpu/drm/i915/intel_i2c.c | 17 +++++++++-------- 1 files changed, 9 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c index 9619bde..7674c89 100644 --- a/drivers/gpu/drm/i915/intel_i2c.c +++ b/drivers/gpu/drm/i915/intel_i2c.c @@ -214,6 +214,7 @@ gmbus_xfer(struct i2c_adapter *adapter, struct drm_i915_private *dev_priv = bus->dev_priv; int i, reg_offset; int ret = 0; + u32 gmbus2 = 0; mutex_lock(&dev_priv->gmbus_mutex); @@ -268,12 +269,12 @@ gmbus_xfer(struct i2c_adapter *adapter, do { u32 val, loop = 0; - if (wait_for(I915_READ(GMBUS2 + reg_offset) & + if (wait_for((gmbus2 = I915_READ(GMBUS2 + + reg_offset)) & (GMBUS_SATOER | GMBUS_HW_RDY), 50)) goto timeout; - if (I915_READ(GMBUS2 + reg_offset) & - GMBUS_SATOER) + if (gmbus2 & GMBUS_SATOER) goto clear_err; val = I915_READ(GMBUS3 + reg_offset); @@ -308,21 +309,21 @@ gmbus_xfer(struct i2c_adapter *adapter, I915_WRITE(GMBUS3 + reg_offset, val); POSTING_READ(GMBUS2 + reg_offset); - if (wait_for(I915_READ(GMBUS2 + reg_offset) & + if (wait_for((gmbus2 = I915_READ(GMBUS2 + + reg_offset)) & (GMBUS_SATOER | GMBUS_HW_RDY), 50)) goto timeout; - if (I915_READ(GMBUS2 + reg_offset) & - GMBUS_SATOER) + if (gmbus2 & GMBUS_SATOER) goto clear_err; } } - if (wait_for(I915_READ(GMBUS2 + reg_offset) & + if (wait_for((gmbus2 = I915_READ(GMBUS2 + reg_offset)) & (GMBUS_SATOER | GMBUS_HW_WAIT_PHASE), 50)) goto timeout; - if (I915_READ(GMBUS2 + reg_offset) & GMBUS_SATOER) + if (gmbus2 & GMBUS_SATOER) goto clear_err; } -- 1.7.7.3
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