[Intel-gfx] [PATCH] drm/i915: Simplify onion for bxt_ddi_phy_init()

Chris Wilson chris at chris-wilson.co.uk
Tue Nov 7 13:53:24 UTC 2017


Older compilers (gcc-4.9) are not as able to track uninitialised
variables as well as more recent compilers. In particular,

drivers/gpu/drm/i915/intel_dpio_phy.c: In function ‘bxt_ddi_phy_init’:
drivers/gpu/drm/i915/intel_dpio_phy.c:482:25: warning: ‘was_enabled’ may be used uninitialized in this function [-Wmaybe-uninitialized]

In this case, we can rearrange code slightly to make the control flow
clearer to the reader, as well as the compiler. That is we only call
uninit using the same predicate as calling init

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira at intel.com>
Cc: Imre Deak <imre.deak at intel.com>
---
 drivers/gpu/drm/i915/intel_dpio_phy.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dpio_phy.c b/drivers/gpu/drm/i915/intel_dpio_phy.c
index 63b76eac018f..490a42d9a3e8 100644
--- a/drivers/gpu/drm/i915/intel_dpio_phy.c
+++ b/drivers/gpu/drm/i915/intel_dpio_phy.c
@@ -466,21 +466,21 @@ void bxt_ddi_phy_init(struct drm_i915_private *dev_priv, enum dpio_phy phy)
 
 	lockdep_assert_held(&dev_priv->power_domains.lock);
 
-	if (rcomp_phy != -1) {
+	was_enabled = true;
+	if (rcomp_phy != -1)
 		was_enabled = bxt_ddi_phy_is_enabled(dev_priv, rcomp_phy);
 
-		/*
-		 * We need to copy the GRC calibration value from rcomp_phy,
-		 * so make sure it's powered up.
-		 */
-		if (!was_enabled)
-			_bxt_ddi_phy_init(dev_priv, rcomp_phy);
-	}
+	/*
+	 * We need to copy the GRC calibration value from rcomp_phy,
+	 * so make sure it's powered up.
+	 */
+	if (!was_enabled)
+		_bxt_ddi_phy_init(dev_priv, rcomp_phy);
 
 	_bxt_ddi_phy_init(dev_priv, phy);
 
-	if (rcomp_phy != -1 && !was_enabled)
-		bxt_ddi_phy_uninit(dev_priv, phy_info->rcomp_phy);
+	if (!was_enabled)
+		bxt_ddi_phy_uninit(dev_priv, rcomp_phy);
 }
 
 static bool __printf(6, 7)
-- 
2.15.0



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