diff mbox series

scsi: ufs-mediatek: Avoid using ret uninitialized in ufs_mtk_setup_clocks

Message ID 20190320180340.25795-1-natechancellor@gmail.com (mailing list archive)
State Mainlined
Commit 1943edacef8966e24fc66d8cbe6347fe8b10ff80
Headers show
Series scsi: ufs-mediatek: Avoid using ret uninitialized in ufs_mtk_setup_clocks | expand

Commit Message

Nathan Chancellor March 20, 2019, 6:03 p.m. UTC
When building with -Wsometimes-uninitialized, Clang warns:

drivers/scsi/ufs/ufs-mediatek.c:112:7: warning: variable 'ret' is used
uninitialized whenever 'if' condition is false
[-Wsometimes-uninitialized]
                if (on)
                    ^~
drivers/scsi/ufs/ufs-mediatek.c:120:9: note: uninitialized use occurs
here
        return ret;
               ^~~
drivers/scsi/ufs/ufs-mediatek.c:112:3: note: remove the 'if' if its
condition is always true
                if (on)
                ^~~~~~~
drivers/scsi/ufs/ufs-mediatek.c:108:7: warning: variable 'ret' is used
uninitialized whenever 'if' condition is false
[-Wsometimes-uninitialized]
                if (!on)
                    ^~~
drivers/scsi/ufs/ufs-mediatek.c:120:9: note: uninitialized use occurs
here
        return ret;
               ^~~
drivers/scsi/ufs/ufs-mediatek.c:108:3: note: remove the 'if' if its
condition is always true
                if (!on)
                ^~~~~~~~
drivers/scsi/ufs/ufs-mediatek.c:96:9: note: initialize the variable
'ret' to silence this warning
        int ret;
               ^
                = 0
2 warnings generated.

Remove the default case and initialize ret to -EINVAL to properly fix
this warning.

Fixes: ddd90623ce26 ("scsi: ufs-mediatek: Add UFS support for Mediatek SoC chips")
Link: https://github.com/ClangBuiltLinux/linux/issues/426
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
---
 drivers/scsi/ufs/ufs-mediatek.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

Comments

Nick Desaulniers March 20, 2019, 10:23 p.m. UTC | #1
On Wed, Mar 20, 2019 at 11:06 AM Nathan Chancellor
<natechancellor@gmail.com> wrote:
>
> When building with -Wsometimes-uninitialized, Clang warns:
>
> drivers/scsi/ufs/ufs-mediatek.c:112:7: warning: variable 'ret' is used
> uninitialized whenever 'if' condition is false
> [-Wsometimes-uninitialized]
>                 if (on)
>                     ^~
> drivers/scsi/ufs/ufs-mediatek.c:120:9: note: uninitialized use occurs
> here
>         return ret;
>                ^~~
> drivers/scsi/ufs/ufs-mediatek.c:112:3: note: remove the 'if' if its
> condition is always true
>                 if (on)
>                 ^~~~~~~
> drivers/scsi/ufs/ufs-mediatek.c:108:7: warning: variable 'ret' is used
> uninitialized whenever 'if' condition is false
> [-Wsometimes-uninitialized]
>                 if (!on)
>                     ^~~
> drivers/scsi/ufs/ufs-mediatek.c:120:9: note: uninitialized use occurs
> here
>         return ret;
>                ^~~
> drivers/scsi/ufs/ufs-mediatek.c:108:3: note: remove the 'if' if its
> condition is always true
>                 if (!on)
>                 ^~~~~~~~
> drivers/scsi/ufs/ufs-mediatek.c:96:9: note: initialize the variable
> 'ret' to silence this warning
>         int ret;
>                ^
>                 = 0
> 2 warnings generated.
>
> Remove the default case and initialize ret to -EINVAL to properly fix
> this warning.
>
> Fixes: ddd90623ce26 ("scsi: ufs-mediatek: Add UFS support for Mediatek SoC chips")
> Link: https://github.com/ClangBuiltLinux/linux/issues/426
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> ---
>  drivers/scsi/ufs/ufs-mediatek.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
> index c3b78fc83d3f..34aecad04468 100644
> --- a/drivers/scsi/ufs/ufs-mediatek.c
> +++ b/drivers/scsi/ufs/ufs-mediatek.c
> @@ -93,7 +93,7 @@ static int ufs_mtk_setup_clocks(struct ufs_hba *hba, bool on,
>                                 enum ufs_notify_change_status status)
>  {
>         struct ufs_mtk_host *host = ufshcd_get_variant(hba);
> -       int ret;
> +       int ret = -EINVAL;
>
>         /*
>          * In case ufs_mtk_init() is not yet done, simply ignore.
> @@ -112,9 +112,6 @@ static int ufs_mtk_setup_clocks(struct ufs_hba *hba, bool on,
>                 if (on)
>                         ret = phy_power_on(host->mphy);
>                 break;
> -       default:
> -               ret = -EINVAL;
> -               break;
>         }
>
>         return ret;
> --
> 2.21.0
>

The enum being switched on (enum ufs_notify_change_status) only has 2
values; so the default case is impossible.  A switch is probably
overkill, but this change is fine as is.  Thanks for sending it.
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Stanley Chu March 20, 2019, 11:23 p.m. UTC | #2
Hi,

On Wed, 2019-03-20 at 15:23 -0700, Nick Desaulniers wrote:
> On Wed, Mar 20, 2019 at 11:06 AM Nathan Chancellor
> <natechancellor@gmail.com> wrote:
> >
> > When building with -Wsometimes-uninitialized, Clang warns:
> >
> > drivers/scsi/ufs/ufs-mediatek.c:112:7: warning: variable 'ret' is used
> > uninitialized whenever 'if' condition is false
> > [-Wsometimes-uninitialized]
> >                 if (on)
> >                     ^~
> > drivers/scsi/ufs/ufs-mediatek.c:120:9: note: uninitialized use occurs
> > here
> >         return ret;
> >                ^~~
> > drivers/scsi/ufs/ufs-mediatek.c:112:3: note: remove the 'if' if its
> > condition is always true
> >                 if (on)
> >                 ^~~~~~~
> > drivers/scsi/ufs/ufs-mediatek.c:108:7: warning: variable 'ret' is used
> > uninitialized whenever 'if' condition is false
> > [-Wsometimes-uninitialized]
> >                 if (!on)
> >                     ^~~
> > drivers/scsi/ufs/ufs-mediatek.c:120:9: note: uninitialized use occurs
> > here
> >         return ret;
> >                ^~~
> > drivers/scsi/ufs/ufs-mediatek.c:108:3: note: remove the 'if' if its
> > condition is always true
> >                 if (!on)
> >                 ^~~~~~~~
> > drivers/scsi/ufs/ufs-mediatek.c:96:9: note: initialize the variable
> > 'ret' to silence this warning
> >         int ret;
> >                ^
> >                 = 0
> > 2 warnings generated.
> >
> > Remove the default case and initialize ret to -EINVAL to properly fix
> > this warning.
> >
> > Fixes: ddd90623ce26 ("scsi: ufs-mediatek: Add UFS support for Mediatek SoC chips")
> > Link: https://github.com/ClangBuiltLinux/linux/issues/426
> > Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> > ---
> >  drivers/scsi/ufs/ufs-mediatek.c | 5 +----
> >  1 file changed, 1 insertion(+), 4 deletions(-)
> >
> > diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
> > index c3b78fc83d3f..34aecad04468 100644
> > --- a/drivers/scsi/ufs/ufs-mediatek.c
> > +++ b/drivers/scsi/ufs/ufs-mediatek.c
> > @@ -93,7 +93,7 @@ static int ufs_mtk_setup_clocks(struct ufs_hba *hba, bool on,
> >                                 enum ufs_notify_change_status status)
> >  {
> >         struct ufs_mtk_host *host = ufshcd_get_variant(hba);
> > -       int ret;
> > +       int ret = -EINVAL;
> >
> >         /*
> >          * In case ufs_mtk_init() is not yet done, simply ignore.
> > @@ -112,9 +112,6 @@ static int ufs_mtk_setup_clocks(struct ufs_hba *hba, bool on,
> >                 if (on)
> >                         ret = phy_power_on(host->mphy);
> >                 break;
> > -       default:
> > -               ret = -EINVAL;
> > -               break;
> >         }
> >
> >         return ret;
> > --
> > 2.21.0
> >
> 
> The enum being switched on (enum ufs_notify_change_status) only has 2
> values; so the default case is impossible.  A switch is probably
> overkill, but this change is fine as is.  Thanks for sending it.
> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

Currently the caller is always using "on" with "POST_CHANGE" and "!on"
with "PRE_CHANGE", however the warnings shall be fixed. Thanks for
fixing it.

Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Martin K. Petersen March 21, 2019, 12:10 a.m. UTC | #3
Nathan,

> Remove the default case and initialize ret to -EINVAL to properly fix
> this warning.

Applied to 5.2/scsi-queue, thanks!
diff mbox series

Patch

diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
index c3b78fc83d3f..34aecad04468 100644
--- a/drivers/scsi/ufs/ufs-mediatek.c
+++ b/drivers/scsi/ufs/ufs-mediatek.c
@@ -93,7 +93,7 @@  static int ufs_mtk_setup_clocks(struct ufs_hba *hba, bool on,
 				enum ufs_notify_change_status status)
 {
 	struct ufs_mtk_host *host = ufshcd_get_variant(hba);
-	int ret;
+	int ret = -EINVAL;
 
 	/*
 	 * In case ufs_mtk_init() is not yet done, simply ignore.
@@ -112,9 +112,6 @@  static int ufs_mtk_setup_clocks(struct ufs_hba *hba, bool on,
 		if (on)
 			ret = phy_power_on(host->mphy);
 		break;
-	default:
-		ret = -EINVAL;
-		break;
 	}
 
 	return ret;