[PATCH v2] staging: greybus: audio: split gb_audio_gb_get_topology()

[adi25charis]

From: Aditya Chari S <adi25charis@xxxxxxxxx>

Split gb_audio_gb_get_topology() into two functions:
gb_audio_gb_get_topology_size() to fetch the topology size, and
gb_audio_gb_get_topology() to fetch the topology data into a
caller-provided buffer. This moves buffer allocation out of the
audio_gb protocol helper and into gb_audio_probe(), where it
belongs, addressing a long-standing FIXME.

Signed-off-by: Aditya Chari S <adi25charis@xxxxxxxxx>
---
v2:
- Store size as size_t instead of u16, per Dan Carpenter.
- Move the size validation (size < sizeof(*topology)) out of
  gb_audio_gb_get_topology() and into gb_audio_probe(), before
  the kzalloc(), per Dan Carpenter.
- Fix dev_err() format strings so %d is no longer printed first;
  put it at the end of the message instead, per Dan Carpenter.

Compile-tested with `make M=drivers/staging/greybus modules`.
All modified files (audio_codec.h, audio_gb.c, audio_module.c)
compile without errors or warnings. checkpatch.pl --no-tree passes
clean on all three files.
---
 drivers/staging/greybus/audio_codec.h  |  4 ++--
 drivers/staging/greybus/audio_gb.c     |  7 ++-----
 drivers/staging/greybus/audio_module.c | 12 +++++++++---
 3 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/staging/greybus/audio_codec.h b/drivers/staging/greybus/audio_codec.h
index be5a2a86b..b45cd257d 100644
--- a/drivers/staging/greybus/audio_codec.h
+++ b/drivers/staging/greybus/audio_codec.h
@@ -179,9 +179,9 @@ void gbaudio_unregister_module(struct gbaudio_module_info *module);
 
 /* protocol related */
 int gb_audio_gb_get_topology_size(struct gb_connection *connection,
-				  u16 *size);
+				  size_t *size);
 int gb_audio_gb_get_topology(struct gb_connection *connection,
-			     struct gb_audio_topology *topology, u16 size);
+			     struct gb_audio_topology *topology, size_t size);
 int gb_audio_gb_get_control(struct gb_connection *connection,
 			    u8 control_id, u8 index,
 			    struct gb_audio_ctl_elem_value *value);
diff --git a/drivers/staging/greybus/audio_gb.c b/drivers/staging/greybus/audio_gb.c
index e6356643d..2e6f155d8 100644
--- a/drivers/staging/greybus/audio_gb.c
+++ b/drivers/staging/greybus/audio_gb.c
@@ -9,7 +9,7 @@
 #include "audio_codec.h"
 
 int gb_audio_gb_get_topology_size(struct gb_connection *connection,
-				  u16 *size)
+				  size_t *size)
 {
 	struct gb_audio_get_topology_size_response size_resp;
 	int ret;
@@ -26,11 +26,8 @@ int gb_audio_gb_get_topology_size(struct gb_connection *connection,
 EXPORT_SYMBOL_GPL(gb_audio_gb_get_topology_size);
 
 int gb_audio_gb_get_topology(struct gb_connection *connection,
-			     struct gb_audio_topology *topology, u16 size)
+			     struct gb_audio_topology *topology, size_t size)
 {
-	if (size < sizeof(*topology))
-		return -ENODATA;
-
 	return gb_operation_sync(connection, GB_AUDIO_TYPE_GET_TOPOLOGY, NULL, 0,
 				 topology, size);
 }
diff --git a/drivers/staging/greybus/audio_module.c b/drivers/staging/greybus/audio_module.c
index 1163cf093..806533f03 100644
--- a/drivers/staging/greybus/audio_module.c
+++ b/drivers/staging/greybus/audio_module.c
@@ -239,7 +239,7 @@ static int gb_audio_probe(struct gb_bundle *bundle,
 	struct gb_audio_manager_module_descriptor desc;
 	struct gbaudio_data_connection *dai, *_dai;
 	int ret, i;
-	u16 size;
+	size_t size;
 	struct gb_audio_topology *topology;
 
 	/* There should be at least one Management and one Data cport */
@@ -307,7 +307,13 @@ static int gb_audio_probe(struct gb_bundle *bundle,
 
 	ret = gb_audio_gb_get_topology_size(gbmodule->mgmt_connection, &size);
 	if (ret) {
-		dev_err(dev, "%d:Error while fetching topology size\n", ret);
+		dev_err(dev, "Error while fetching topology size: %d\n", ret);
+		goto disable_connection;
+	}
+
+	if (size < sizeof(*topology)) {
+		dev_err(dev, "Invalid topology size: %zu\n", size);
+		ret = -ENODATA;
 		goto disable_connection;
 	}
 
@@ -319,7 +325,7 @@ static int gb_audio_probe(struct gb_bundle *bundle,
 
 	ret = gb_audio_gb_get_topology(gbmodule->mgmt_connection, topology, size);
 	if (ret) {
-		dev_err(dev, "%d:Error while fetching topology\n", ret);
+		dev_err(dev, "Error while fetching topology: %d\n", ret);
 		goto free_topology;
 	}
 
-- 
2.53.0