[PATCH] drm/i915/display: fix uninitialized variable

From: trix
Date: Tue Aug 25 2020 - 19:21:18 EST


From: Tom Rix <trix@xxxxxxxxxx>

clang static analysis flags this error

intel_combo_phy.c:268:7: warning: The left expression of the
compound assignment is an uninitialized value.
The computed value will also be garbage
ret &= check_phy_reg(...
~~~ ^

ret has no initial values, in icl_combo_phy_verify_state() ret is
set by the next statment and then updated by similar &= logic.

Because the check_phy_req() are only register reads, reorder the
statements.

Fixes: 239bef676d8e ("drm/i915/display: Implement new combo phy initialization step")
Signed-off-by: Tom Rix <trix@xxxxxxxxxx>
---
drivers/gpu/drm/i915/display/intel_combo_phy.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_combo_phy.c b/drivers/gpu/drm/i915/display/intel_combo_phy.c
index 6968de4f3477..7622ef66c987 100644
--- a/drivers/gpu/drm/i915/display/intel_combo_phy.c
+++ b/drivers/gpu/drm/i915/display/intel_combo_phy.c
@@ -264,6 +264,8 @@ static bool icl_combo_phy_verify_state(struct drm_i915_private *dev_priv,
if (!icl_combo_phy_enabled(dev_priv, phy))
return false;

+ ret = cnl_verify_procmon_ref_values(dev_priv, phy);
+
if (INTEL_GEN(dev_priv) >= 12) {
ret &= check_phy_reg(dev_priv, phy, ICL_PORT_TX_DW8_LN0(phy),
ICL_PORT_TX_DW8_ODCC_CLK_SEL |
@@ -276,8 +278,6 @@ static bool icl_combo_phy_verify_state(struct drm_i915_private *dev_priv,
DCC_MODE_SELECT_CONTINUOSLY);
}

- ret = cnl_verify_procmon_ref_values(dev_priv, phy);
-
if (phy_is_master(dev_priv, phy)) {
ret &= check_phy_reg(dev_priv, phy, ICL_PORT_COMP_DW8(phy),
IREFGEN, IREFGEN);
--
2.18.1