ASoC: wm_adsp: Don't overwrite fwf_name with the default

There's no need to overwrite fwf_name with a kstrdup() of the cs_dsp part
name. It is trivial to select either fwf_name or cs_dsp.part as the string
to use when building the filename in wm_adsp_request_firmware_file().

This leaves fwf_name entirely owned by the codec driver.

It also avoids problems with freeing the pointer. With the original code
fwf_name was either a pointer owned by the codec driver, or a kstrdup()
created by wm_adsp. This meant wm_adsp must free it if it set it, but not
if the codec driver set it. The code was handling this by using
devm_kstrdup().
But there is no absolute requirement that wm_adsp_common_init() must be
called from probe(), so this was a pseudo-memory leak - each new call to
wm_adsp_common_init() would allocate another block of memory but these
would only be freed if the owning codec driver was removed.
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://msgid.link/r/20240129162737.497-3-rf@opensource.cirrus.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/wm_adsp.c

@@ -739,19 +739,25 @@ static int wm_adsp_request_firmware_file(struct wm_adsp *dsp,
 					 const char *filetype)
 {
 	struct cs_dsp *cs_dsp = &dsp->cs_dsp;
+	const char *fwf;
 	char *s, c;
 	int ret = 0;
 
+	if (dsp->fwf_name)
+		fwf = dsp->fwf_name;
+	else
+		fwf = dsp->cs_dsp.name;
+
 	if (system_name && asoc_component_prefix)
 		*filename = kasprintf(GFP_KERNEL, "%s%s-%s-%s-%s-%s.%s", dir, dsp->part,
-				      dsp->fwf_name, wm_adsp_fw[dsp->fw].file, system_name,
+				      fwf, wm_adsp_fw[dsp->fw].file, system_name,
 				      asoc_component_prefix, filetype);
 	else if (system_name)
 		*filename = kasprintf(GFP_KERNEL, "%s%s-%s-%s-%s.%s", dir, dsp->part,
-				      dsp->fwf_name, wm_adsp_fw[dsp->fw].file, system_name,
+				      fwf, wm_adsp_fw[dsp->fw].file, system_name,
 				      filetype);
 	else
-		*filename = kasprintf(GFP_KERNEL, "%s%s-%s-%s.%s", dir, dsp->part, dsp->fwf_name,
+		*filename = kasprintf(GFP_KERNEL, "%s%s-%s-%s.%s", dir, dsp->part, fwf,
 				      wm_adsp_fw[dsp->fw].file, filetype);
 
 	if (*filename == NULL)
@@ -857,29 +863,18 @@ static int wm_adsp_request_firmware_files(struct wm_adsp *dsp,
 	}
 
 	adsp_err(dsp, "Failed to request firmware <%s>%s-%s-%s<-%s<%s>>.wmfw\n",
-		 cirrus_dir, dsp->part, dsp->fwf_name, wm_adsp_fw[dsp->fw].file,
-		 system_name, asoc_component_prefix);
+		 cirrus_dir, dsp->part,
+		 dsp->fwf_name ? dsp->fwf_name : dsp->cs_dsp.name,
+		 wm_adsp_fw[dsp->fw].file, system_name, asoc_component_prefix);
 
 	return -ENOENT;
 }
 
 static int wm_adsp_common_init(struct wm_adsp *dsp)
 {
-	char *p;
-
 	INIT_LIST_HEAD(&dsp->compr_list);
 	INIT_LIST_HEAD(&dsp->buffer_list);
 
-	if (!dsp->fwf_name) {
-		p = devm_kstrdup(dsp->cs_dsp.dev, dsp->cs_dsp.name, GFP_KERNEL);
-		if (!p)
-			return -ENOMEM;
-
-		dsp->fwf_name = p;
-		for (; *p != 0; ++p)
-			*p = tolower(*p);
-	}
-
 	return 0;
 }