linux-kernel - [PATCH 01/10] drm/imagination: avoid unused-const-variable warning

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Message-Id: <20250409122314.2848028-1-arnd@kernel.org>
Date: Wed,  9 Apr 2025 14:22:53 +0200
From: Arnd Bergmann <arnd@...nel.org>
To: Frank Binns <frank.binns@...tec.com>,
	Matt Coster <matt.coster@...tec.com>,
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	David Airlie <airlied@...il.com>,
	Simona Vetter <simona@...ll.ch>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>,
	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
	Arnd Bergmann <arnd@...db.de>,
	Andrzej Hajda <andrzej.hajda@...el.com>,
	Jani Nikula <jani.nikula@...el.com>,
	Alex Deucher <alexander.deucher@....com>,
	Alessio Belle <alessio.belle@...tec.com>,
	dri-devel@...ts.freedesktop.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH 01/10] drm/imagination: avoid unused-const-variable warning

From: Arnd Bergmann <arnd@...db.de>

When CONFIG_DEBUG_FS is disabled, the stid_fmts[] array is not referenced
anywhere, causing a W=1 warning with gcc:

In file included from drivers/gpu/drm/imagination/pvr_fw_trace.c:7:
drivers/gpu/drm/imagination/pvr_rogue_fwif_sf.h:75:39: error: 'stid_fmts' defined but not used [-Werror=unused-const-variable=]
   75 | static const struct rogue_km_stid_fmt stid_fmts[] = {
      |                                       ^~~~~~~~~

Rather than adding more #ifdef blocks, address this by changing the
existing #ifdef into equivalent IS_ENABLED() checks so gcc can see
where the symbol is used but still eliminate it from the object file.

Signed-off-by: Arnd Bergmann <arnd@...db.de>
---
 drivers/gpu/drm/imagination/pvr_fw_trace.c | 8 ++++----
 drivers/gpu/drm/imagination/pvr_fw_trace.h | 2 --
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/imagination/pvr_fw_trace.c b/drivers/gpu/drm/imagination/pvr_fw_trace.c
index 5dbb636d7d4f..93269299d6a4 100644
--- a/drivers/gpu/drm/imagination/pvr_fw_trace.c
+++ b/drivers/gpu/drm/imagination/pvr_fw_trace.c
@@ -122,8 +122,6 @@ void pvr_fw_trace_fini(struct pvr_device *pvr_dev)
 	pvr_fw_object_unmap_and_destroy(fw_trace->tracebuf_ctrl_obj);
 }
 
-#if defined(CONFIG_DEBUG_FS)
-
 /**
  * update_logtype() - Send KCCB command to trigger FW to update logtype
  * @pvr_dev: Target PowerVR device
@@ -447,7 +445,7 @@ static const struct file_operations pvr_fw_trace_fops = {
 void
 pvr_fw_trace_mask_update(struct pvr_device *pvr_dev, u32 old_mask, u32 new_mask)
 {
-	if (old_mask != new_mask)
+	if (IS_ENABLED(CONFIG_DEBUG_FS) && old_mask != new_mask)
 		update_logtype(pvr_dev, new_mask);
 }
 
@@ -457,6 +455,9 @@ pvr_fw_trace_debugfs_init(struct pvr_device *pvr_dev, struct dentry *dir)
 	struct pvr_fw_trace *fw_trace = &pvr_dev->fw_dev.fw_trace;
 	u32 thread_nr;
 
+	if (!IS_ENABLED(CONFIG_DEBUG_FS))
+		return;
+
 	static_assert(ARRAY_SIZE(fw_trace->buffers) <= 10,
 		      "The filename buffer is only large enough for a single-digit thread count");
 
@@ -469,4 +470,3 @@ pvr_fw_trace_debugfs_init(struct pvr_device *pvr_dev, struct dentry *dir)
 				    &pvr_fw_trace_fops);
 	}
 }
-#endif
diff --git a/drivers/gpu/drm/imagination/pvr_fw_trace.h b/drivers/gpu/drm/imagination/pvr_fw_trace.h
index 0074d2b18da0..1d0ef937427a 100644
--- a/drivers/gpu/drm/imagination/pvr_fw_trace.h
+++ b/drivers/gpu/drm/imagination/pvr_fw_trace.h
@@ -65,7 +65,6 @@ struct pvr_fw_trace {
 int pvr_fw_trace_init(struct pvr_device *pvr_dev);
 void pvr_fw_trace_fini(struct pvr_device *pvr_dev);
 
-#if defined(CONFIG_DEBUG_FS)
 /* Forward declaration from <linux/dcache.h>. */
 struct dentry;
 
@@ -73,6 +72,5 @@ void pvr_fw_trace_mask_update(struct pvr_device *pvr_dev, u32 old_mask,
 			      u32 new_mask);
 
 void pvr_fw_trace_debugfs_init(struct pvr_device *pvr_dev, struct dentry *dir);
-#endif /* defined(CONFIG_DEBUG_FS) */
 
 #endif /* PVR_FW_TRACE_H */
-- 
2.39.5