linux-kernel - [PATCH v2 1/1] drm/i915/dsi: Drop double check ACPI companion device for NULL

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Date:   Wed, 22 Dec 2021 17:40:33 +0200
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        intel-gfx@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org,
        linux-kernel@...r.kernel.org
Cc:     Jani Nikula <jani.nikula@...ux.intel.com>,
        Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>,
        Rodrigo Vivi <rodrigo.vivi@...el.com>,
        Tvrtko Ursulin <tvrtko.ursulin@...ux.intel.com>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        Ville Syrjälä 
        <ville.syrjala@...ux.intel.com>
Subject: [PATCH v2 1/1] drm/i915/dsi: Drop double check ACPI companion device for NULL

acpi_dev_get_resources() does perform the NULL pointer check against
ACPI companion device which is given as function parameter. Thus,
there is no need to duplicate this check in the caller.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
---
v2: used LIST_HEAD() (Ville), initialized lookup directly on stack (Ville)
 drivers/gpu/drm/i915/display/intel_dsi_vbt.c | 28 +++++++-------------
 1 file changed, 10 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dsi_vbt.c b/drivers/gpu/drm/i915/display/intel_dsi_vbt.c
index 0da91849efde..da0bd056f3d3 100644
--- a/drivers/gpu/drm/i915/display/intel_dsi_vbt.c
+++ b/drivers/gpu/drm/i915/display/intel_dsi_vbt.c
@@ -426,24 +426,16 @@ static void i2c_acpi_find_adapter(struct intel_dsi *intel_dsi,
 				  const u16 slave_addr)
 {
 	struct drm_device *drm_dev = intel_dsi->base.base.dev;
-	struct device *dev = drm_dev->dev;
-	struct acpi_device *acpi_dev;
-	struct list_head resource_list;
-	struct i2c_adapter_lookup lookup;
-
-	acpi_dev = ACPI_COMPANION(dev);
-	if (acpi_dev) {
-		memset(&lookup, 0, sizeof(lookup));
-		lookup.slave_addr = slave_addr;
-		lookup.intel_dsi = intel_dsi;
-		lookup.dev_handle = acpi_device_handle(acpi_dev);
-
-		INIT_LIST_HEAD(&resource_list);
-		acpi_dev_get_resources(acpi_dev, &resource_list,
-				       i2c_adapter_lookup,
-				       &lookup);
-		acpi_dev_free_resource_list(&resource_list);
-	}
+	struct acpi_device *adev = ACPI_COMPANION(drm_dev->dev);
+	struct i2c_adapter_lookup lookup = {
+		.slave_addr = slave_addr,
+		.intel_dsi = intel_dsi,
+		.dev_handle = acpi_device_handle(adev),
+	};
+	LIST_HEAD(resource_list);
+
+	acpi_dev_get_resources(adev, &resource_list, i2c_adapter_lookup, &lookup);
+	acpi_dev_free_resource_list(&resource_list);
 }
 #else
 static inline void i2c_acpi_find_adapter(struct intel_dsi *intel_dsi,
-- 
2.34.1