| Message ID | 20190320180340.25795-1-natechancellor@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | scsi: ufs-mediatek: Avoid using ret uninitialized in ufs_mtk_setup_clocks | expand |
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>
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>
Nathan, > Remove the default case and initialize ret to -EINVAL to properly fix > this warning. Applied to 5.2/scsi-queue, thanks!
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;
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(-)