drm/i915: add support for SBI ops

[Dan Carpenter]

Hello Eugeni Dodonov,

The patch a416edefbbaf: "drm/i915: add support for SBI ops" from May
9, 2012, leads to the following warning:
drivers/gpu/drm/i915/intel_display.c:1347 intel_sbi_write()
	 warn: bitwise AND condition is false here

SBI_READY is defined like this:

#define  SBI_READY                              (0x0<<0)

  1346          spin_lock_irqsave(&dev_priv->dpio_lock, flags);
  1347          if (wait_for((I915_READ(SBI_CTL_STAT) & SBI_READY) == 0,

	if ((x & 0) == 0) { ...

This is always true, so this condition will never timeout.

  1348                                  100)) {
  1349                  DRM_ERROR("timeout waiting for SBI to become ready\n");
  1350                  goto out_unlock;
  1351          }

All the places that use SBI_READY are like this:

drivers/gpu/drm/i915/intel_display.c:1347 intel_sbi_write() warn: bitwise AND condition is false here
drivers/gpu/drm/i915/intel_display.c:1361 intel_sbi_write() warn: bitwise AND condition is false here
drivers/gpu/drm/i915/intel_display.c:1378 intel_sbi_read() warn: bitwise AND condition is false here
drivers/gpu/drm/i915/intel_display.c:1390 intel_sbi_read() warn: bitwise AND condition is false here

regards,
dan carpenter