coresight: catu: fix clang build warning

Clang points out a syntax error, as the etr_catu_buf_ops structure is
declared 'static' before the type is known:

In file included from drivers/hwtracing/coresight/coresight-tmc-etr.c:12:
drivers/hwtracing/coresight/coresight-catu.h:116:40: warning: tentative definition of variable with internal linkage has incomplete non-array type 'const struct etr_buf_operations' [-Wtentative-definition-incomplete-type]
static const struct etr_buf_operations etr_catu_buf_ops;
                                       ^
drivers/hwtracing/coresight/coresight-catu.h:116:21: note: forward declaration of 'struct etr_buf_operations'
static const struct etr_buf_operations etr_catu_buf_ops;

This seems worth fixing in the code, so replace pointer to the empty
constant structure with a NULL pointer. We need an extra NULL pointer
check here, but the result should be better object code otherwise,
avoiding the silly empty structure.

Fixes: 434d611cddef ("coresight: catu: Plug in CATU as a backend for ETR buffer")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
[Fixed line over 80 characters]
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/hwtracing/coresight/coresight-catu.h b/drivers/hwtracing/coresight/coresight-catu.h
index 1b281f0dccccace70e33bd6b26e532e2b6844ef2..1d2ad183fd92d25932b751ff4f40342c17cfab61 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-catu.h
+++ b/drivers/hwtracing/coresight/coresight-catu.h
@@ -109,11 +109,6 @@ static inline bool coresight_is_catu_device(struct coresight_device *csdev)
        return true;
 }
 
-#ifdef CONFIG_CORESIGHT_CATU
 extern const struct etr_buf_operations etr_catu_buf_ops;
-#else
-/* Dummy declaration for the CATU ops */
-static const struct etr_buf_operations etr_catu_buf_ops;
-#endif
 
 #endif

diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index f684283890d3d1810d937fcf627948ad3f33546a..cf7a32ce209d3e27f7191d01853fe85f2bf14080 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -772,7 +772,8 @@ static inline void tmc_etr_disable_catu(struct tmc_drvdata *drvdata)
 static const struct etr_buf_operations *etr_buf_ops[] = {
        [ETR_MODE_FLAT] = &etr_flat_buf_ops,
        [ETR_MODE_ETR_SG] = &etr_sg_buf_ops,
-       [ETR_MODE_CATU] = &etr_catu_buf_ops,
+       [ETR_MODE_CATU] = IS_ENABLED(CONFIG_CORESIGHT_CATU)
+                                               ? &etr_catu_buf_ops : NULL,
 };
 
 static inline int tmc_etr_mode_alloc_buf(int mode,
@@ -786,7 +787,7 @@ static inline int tmc_etr_mode_alloc_buf(int mode,
        case ETR_MODE_FLAT:
        case ETR_MODE_ETR_SG:
        case ETR_MODE_CATU:
-               if (etr_buf_ops[mode]->alloc)
+               if (etr_buf_ops[mode] && etr_buf_ops[mode]->alloc)
                        rc = etr_buf_ops[mode]->alloc(drvdata, etr_buf,
                                                      node, pages);
                if (!rc)