ALSA: hda/ca0132: work around clang -Wuninitialized warning

Message ID 20190322140649.197027-1-arnd@arndb.de
State New
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Series
  • ALSA: hda/ca0132: work around clang -Wuninitialized warning
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Commit Message

Arnd Bergmann March 22, 2019, 2:06 p.m.
When CONFIG_PCI is disabled, clang gets confused about the
control flow of the switch() statement always ending up
in the default case, and warns:

sound/pci/hda/patch_ca0132.c:7558:6: error: variable 'fw_entry' is used uninitialized whenever 'if' condition is false
      [-Werror,-Wsometimes-uninitialized]
        if (!spec->alt_firmware_present) {
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~
sound/pci/hda/patch_ca0132.c:7565:42: note: uninitialized use occurs here
        dsp_os_image = (struct dsp_image_seg *)(fw_entry->data);
                                                ^~~~~~~~
sound/pci/hda/patch_ca0132.c:7558:2: note: remove the 'if' if its condition is always true
        if (!spec->alt_firmware_present) {
        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
sound/pci/hda/patch_ca0132.c:7521:33: note: initialize the variable 'fw_entry' to silence this warning
        const struct firmware *fw_entry;
                                       ^
                                        = NULL

Adding an explicit check for CONFIG_PCI avoids the issue.
Unfortunately this is not very intuitive here.

Link: https://bugs.llvm.org/show_bug.cgi?id=41197#c1
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

---
Any suggestions for other workarounds appreciated. If you can think
of a better fix, please treat this as a reported-by:
---
 sound/pci/hda/patch_ca0132.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

-- 
2.20.0

Comments

Nathan Chancellor March 22, 2019, 2:53 p.m. | #1
On Fri, Mar 22, 2019 at 03:06:28PM +0100, Arnd Bergmann wrote:
> When CONFIG_PCI is disabled, clang gets confused about the

> control flow of the switch() statement always ending up

> in the default case, and warns:

> 

> sound/pci/hda/patch_ca0132.c:7558:6: error: variable 'fw_entry' is used uninitialized whenever 'if' condition is false

>       [-Werror,-Wsometimes-uninitialized]

>         if (!spec->alt_firmware_present) {

>             ^~~~~~~~~~~~~~~~~~~~~~~~~~~

> sound/pci/hda/patch_ca0132.c:7565:42: note: uninitialized use occurs here

>         dsp_os_image = (struct dsp_image_seg *)(fw_entry->data);

>                                                 ^~~~~~~~

> sound/pci/hda/patch_ca0132.c:7558:2: note: remove the 'if' if its condition is always true

>         if (!spec->alt_firmware_present) {

>         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

> sound/pci/hda/patch_ca0132.c:7521:33: note: initialize the variable 'fw_entry' to silence this warning

>         const struct firmware *fw_entry;

>                                        ^

>                                         = NULL

> 

> Adding an explicit check for CONFIG_PCI avoids the issue.

> Unfortunately this is not very intuitive here.

> 

> Link: https://bugs.llvm.org/show_bug.cgi?id=41197#c1

> Signed-off-by: Arnd Bergmann <arnd@arndb.de>


Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>


> ---

> Any suggestions for other workarounds appreciated. If you can think

> of a better fix, please treat this as a reported-by:

> ---

>  sound/pci/hda/patch_ca0132.c | 2 +-

>  1 file changed, 1 insertion(+), 1 deletion(-)

> 

> diff --git a/sound/pci/hda/patch_ca0132.c b/sound/pci/hda/patch_ca0132.c

> index 29882bda7632..415b16b7db70 100644

> --- a/sound/pci/hda/patch_ca0132.c

> +++ b/sound/pci/hda/patch_ca0132.c

> @@ -7555,7 +7555,7 @@ static bool ca0132_download_dsp_images(struct hda_codec *codec)

>  	 * Use default ctefx.bin if no alt firmware is detected, or if none

>  	 * exists for your particular codec.

>  	 */

> -	if (!spec->alt_firmware_present) {

> +	if (!IS_ENABLED(CONFIG_PCI) || !spec->alt_firmware_present) {

>  		codec_dbg(codec, "Default firmware selected.");

>  		if (request_firmware(&fw_entry, EFX_FILE,

>  					codec->card->dev) != 0)

> -- 

> 2.20.0

>
Takashi Iwai March 22, 2019, 3 p.m. | #2
On Fri, 22 Mar 2019 15:06:28 +0100,
Arnd Bergmann wrote:
> 

> When CONFIG_PCI is disabled, clang gets confused about the

> control flow of the switch() statement always ending up

> in the default case, and warns:

> 

> sound/pci/hda/patch_ca0132.c:7558:6: error: variable 'fw_entry' is used uninitialized whenever 'if' condition is false

>       [-Werror,-Wsometimes-uninitialized]

>         if (!spec->alt_firmware_present) {

>             ^~~~~~~~~~~~~~~~~~~~~~~~~~~

> sound/pci/hda/patch_ca0132.c:7565:42: note: uninitialized use occurs here

>         dsp_os_image = (struct dsp_image_seg *)(fw_entry->data);

>                                                 ^~~~~~~~

> sound/pci/hda/patch_ca0132.c:7558:2: note: remove the 'if' if its condition is always true

>         if (!spec->alt_firmware_present) {

>         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

> sound/pci/hda/patch_ca0132.c:7521:33: note: initialize the variable 'fw_entry' to silence this warning

>         const struct firmware *fw_entry;

>                                        ^

>                                         = NULL

> 

> Adding an explicit check for CONFIG_PCI avoids the issue.

> Unfortunately this is not very intuitive here.

> 

> Link: https://bugs.llvm.org/show_bug.cgi?id=41197#c1

> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

> ---

> Any suggestions for other workarounds appreciated. If you can think

> of a better fix, please treat this as a reported-by:


Can it be addressed by the code simplification like below, instead?


thanks,

Takashi

---
 sound/pci/hda/patch_ca0132.c | 20 ++++++--------------
 1 file changed, 6 insertions(+), 14 deletions(-)

diff --git a/sound/pci/hda/patch_ca0132.c b/sound/pci/hda/patch_ca0132.c
index 29882bda7632..e1ebc6d5f382 100644
--- a/sound/pci/hda/patch_ca0132.c
+++ b/sound/pci/hda/patch_ca0132.c
@@ -1005,7 +1005,6 @@ struct ca0132_spec {
 	unsigned int scp_resp_header;
 	unsigned int scp_resp_data[4];
 	unsigned int scp_resp_count;
-	bool alt_firmware_present;
 	bool startup_check_entered;
 	bool dsp_reload;
 
@@ -7518,7 +7517,7 @@ static bool ca0132_download_dsp_images(struct hda_codec *codec)
 	bool dsp_loaded = false;
 	struct ca0132_spec *spec = codec->spec;
 	const struct dsp_image_seg *dsp_os_image;
-	const struct firmware *fw_entry;
+	const struct firmware *fw_entry = NULL;
 	/*
 	 * Alternate firmwares for different variants. The Recon3Di apparently
 	 * can use the default firmware, but I'll leave the option in case
@@ -7529,33 +7528,26 @@ static bool ca0132_download_dsp_images(struct hda_codec *codec)
 	case QUIRK_R3D:
 	case QUIRK_AE5:
 		if (request_firmware(&fw_entry, DESKTOP_EFX_FILE,
-					codec->card->dev) != 0) {
+					codec->card->dev) != 0)
 			codec_dbg(codec, "Desktop firmware not found.");
-			spec->alt_firmware_present = false;
-		} else {
+		else
 			codec_dbg(codec, "Desktop firmware selected.");
-			spec->alt_firmware_present = true;
-		}
 		break;
 	case QUIRK_R3DI:
 		if (request_firmware(&fw_entry, R3DI_EFX_FILE,
-					codec->card->dev) != 0) {
+					codec->card->dev) != 0)
 			codec_dbg(codec, "Recon3Di alt firmware not detected.");
-			spec->alt_firmware_present = false;
-		} else {
+		else
 			codec_dbg(codec, "Recon3Di firmware selected.");
-			spec->alt_firmware_present = true;
-		}
 		break;
 	default:
-		spec->alt_firmware_present = false;
 		break;
 	}
 	/*
 	 * Use default ctefx.bin if no alt firmware is detected, or if none
 	 * exists for your particular codec.
 	 */
-	if (!spec->alt_firmware_present) {
+	if (!fw_entry) {
 		codec_dbg(codec, "Default firmware selected.");
 		if (request_firmware(&fw_entry, EFX_FILE,
 					codec->card->dev) != 0)
-- 
2.16.4
Arnd Bergmann March 22, 2019, 3:12 p.m. | #3
On Fri, Mar 22, 2019 at 4:00 PM Takashi Iwai <tiwai@suse.de> wrote:
>

> On Fri, 22 Mar 2019 15:06:28 +0100,

> Arnd Bergmann wrote:

> >

> > When CONFIG_PCI is disabled, clang gets confused about the

> > control flow of the switch() statement always ending up

> > in the default case, and warns:

> >

> > sound/pci/hda/patch_ca0132.c:7558:6: error: variable 'fw_entry' is used uninitialized whenever 'if' condition is false

> >       [-Werror,-Wsometimes-uninitialized]

> >         if (!spec->alt_firmware_present) {

> >             ^~~~~~~~~~~~~~~~~~~~~~~~~~~

> > sound/pci/hda/patch_ca0132.c:7565:42: note: uninitialized use occurs here

> >         dsp_os_image = (struct dsp_image_seg *)(fw_entry->data);

> >                                                 ^~~~~~~~

> > sound/pci/hda/patch_ca0132.c:7558:2: note: remove the 'if' if its condition is always true

> >         if (!spec->alt_firmware_present) {

> >         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

> > sound/pci/hda/patch_ca0132.c:7521:33: note: initialize the variable 'fw_entry' to silence this warning

> >         const struct firmware *fw_entry;

> >                                        ^

> >                                         = NULL

> >

> > Adding an explicit check for CONFIG_PCI avoids the issue.

> > Unfortunately this is not very intuitive here.

> >

> > Link: https://bugs.llvm.org/show_bug.cgi?id=41197#c1

> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>

> > ---

> > Any suggestions for other workarounds appreciated. If you can think

> > of a better fix, please treat this as a reported-by:

>

> Can it be addressed by the code simplification like below, instead?

>


Yes, I confirmed this works as well, and it's probably more
obvious what's going on, so let's use your version.

Thanks,

      Arnd
Nathan Chancellor March 22, 2019, 3:13 p.m. | #4
On Fri, Mar 22, 2019 at 04:00:19PM +0100, Takashi Iwai wrote:
> On Fri, 22 Mar 2019 15:06:28 +0100,

> Arnd Bergmann wrote:

> > 

> > When CONFIG_PCI is disabled, clang gets confused about the

> > control flow of the switch() statement always ending up

> > in the default case, and warns:

> > 

> > sound/pci/hda/patch_ca0132.c:7558:6: error: variable 'fw_entry' is used uninitialized whenever 'if' condition is false

> >       [-Werror,-Wsometimes-uninitialized]

> >         if (!spec->alt_firmware_present) {

> >             ^~~~~~~~~~~~~~~~~~~~~~~~~~~

> > sound/pci/hda/patch_ca0132.c:7565:42: note: uninitialized use occurs here

> >         dsp_os_image = (struct dsp_image_seg *)(fw_entry->data);

> >                                                 ^~~~~~~~

> > sound/pci/hda/patch_ca0132.c:7558:2: note: remove the 'if' if its condition is always true

> >         if (!spec->alt_firmware_present) {

> >         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

> > sound/pci/hda/patch_ca0132.c:7521:33: note: initialize the variable 'fw_entry' to silence this warning

> >         const struct firmware *fw_entry;

> >                                        ^

> >                                         = NULL

> > 

> > Adding an explicit check for CONFIG_PCI avoids the issue.

> > Unfortunately this is not very intuitive here.

> > 

> > Link: https://bugs.llvm.org/show_bug.cgi?id=41197#c1

> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>

> > ---

> > Any suggestions for other workarounds appreciated. If you can think

> > of a better fix, please treat this as a reported-by:

> 

> Can it be addressed by the code simplification like below, instead?

> 


Yes, the warning is fixed with that diff and makes the code easier to
follow I think.

Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>


> 

> thanks,

> 

> Takashi

> 

> ---

>  sound/pci/hda/patch_ca0132.c | 20 ++++++--------------

>  1 file changed, 6 insertions(+), 14 deletions(-)

> 

> diff --git a/sound/pci/hda/patch_ca0132.c b/sound/pci/hda/patch_ca0132.c

> index 29882bda7632..e1ebc6d5f382 100644

> --- a/sound/pci/hda/patch_ca0132.c

> +++ b/sound/pci/hda/patch_ca0132.c

> @@ -1005,7 +1005,6 @@ struct ca0132_spec {

>  	unsigned int scp_resp_header;

>  	unsigned int scp_resp_data[4];

>  	unsigned int scp_resp_count;

> -	bool alt_firmware_present;

>  	bool startup_check_entered;

>  	bool dsp_reload;

>  

> @@ -7518,7 +7517,7 @@ static bool ca0132_download_dsp_images(struct hda_codec *codec)

>  	bool dsp_loaded = false;

>  	struct ca0132_spec *spec = codec->spec;

>  	const struct dsp_image_seg *dsp_os_image;

> -	const struct firmware *fw_entry;

> +	const struct firmware *fw_entry = NULL;

>  	/*

>  	 * Alternate firmwares for different variants. The Recon3Di apparently

>  	 * can use the default firmware, but I'll leave the option in case

> @@ -7529,33 +7528,26 @@ static bool ca0132_download_dsp_images(struct hda_codec *codec)

>  	case QUIRK_R3D:

>  	case QUIRK_AE5:

>  		if (request_firmware(&fw_entry, DESKTOP_EFX_FILE,

> -					codec->card->dev) != 0) {

> +					codec->card->dev) != 0)

>  			codec_dbg(codec, "Desktop firmware not found.");

> -			spec->alt_firmware_present = false;

> -		} else {

> +		else

>  			codec_dbg(codec, "Desktop firmware selected.");

> -			spec->alt_firmware_present = true;

> -		}

>  		break;

>  	case QUIRK_R3DI:

>  		if (request_firmware(&fw_entry, R3DI_EFX_FILE,

> -					codec->card->dev) != 0) {

> +					codec->card->dev) != 0)

>  			codec_dbg(codec, "Recon3Di alt firmware not detected.");

> -			spec->alt_firmware_present = false;

> -		} else {

> +		else

>  			codec_dbg(codec, "Recon3Di firmware selected.");

> -			spec->alt_firmware_present = true;

> -		}

>  		break;

>  	default:

> -		spec->alt_firmware_present = false;

>  		break;

>  	}

>  	/*

>  	 * Use default ctefx.bin if no alt firmware is detected, or if none

>  	 * exists for your particular codec.

>  	 */

> -	if (!spec->alt_firmware_present) {

> +	if (!fw_entry) {

>  		codec_dbg(codec, "Default firmware selected.");

>  		if (request_firmware(&fw_entry, EFX_FILE,

>  					codec->card->dev) != 0)

> -- 

> 2.16.4

>

Patch

diff --git a/sound/pci/hda/patch_ca0132.c b/sound/pci/hda/patch_ca0132.c
index 29882bda7632..415b16b7db70 100644
--- a/sound/pci/hda/patch_ca0132.c
+++ b/sound/pci/hda/patch_ca0132.c
@@ -7555,7 +7555,7 @@  static bool ca0132_download_dsp_images(struct hda_codec *codec)
 	 * Use default ctefx.bin if no alt firmware is detected, or if none
 	 * exists for your particular codec.
 	 */
-	if (!spec->alt_firmware_present) {
+	if (!IS_ENABLED(CONFIG_PCI) || !spec->alt_firmware_present) {
 		codec_dbg(codec, "Default firmware selected.");
 		if (request_firmware(&fw_entry, EFX_FILE,
 					codec->card->dev) != 0)