Clang warns:
drivers/net/ethernet/intel/igc/igc_mac.c:374:6: warning: variable 'link'
is used uninitialized whenever 'if' condition is true
[-Wsometimes-uninitialized]
if (!mac->get_link_status) {
^~~~~~~~~~~~~~~~~~~~~
drivers/net/ethernet/intel/igc/igc_mac.c:424:33: note: uninitialized use
occurs here
ret_val = igc_set_ltr_i225(hw, link);
^~~~
drivers/net/ethernet/intel/igc/igc_mac.c:374:2: note: remove the 'if' if
its condition is always false
if (!mac->get_link_status) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/ethernet/intel/igc/igc_mac.c:367:11: note: initialize the
variable 'link' to silence this warning
bool link;
^
= 0
1 warning generated.
It is not wrong, link is only uninitialized after this through
igc_phy_has_link. Presumably, if we skip the majority of this function
when get_link_status is false, we should skip calling igc_set_ltr_i225
as well. Just directly return 0 in this case, rather than bothering with
adding another label or initializing link in the if statement.
Fixes: 707abf069548 ("igc: Add initial LTR support")
Link: https://github.com/ClangBuiltLinux/linux/issues/1095
Signed-off-by: Nathan Chancellor <[email protected]>
---
drivers/net/ethernet/intel/igc/igc_mac.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/intel/igc/igc_mac.c b/drivers/net/ethernet/intel/igc/igc_mac.c
index b47e7b0a6398..26e3c56a4a8b 100644
--- a/drivers/net/ethernet/intel/igc/igc_mac.c
+++ b/drivers/net/ethernet/intel/igc/igc_mac.c
@@ -371,10 +371,8 @@ s32 igc_check_for_copper_link(struct igc_hw *hw)
* get_link_status flag is set upon receiving a Link Status
* Change or Rx Sequence Error interrupt.
*/
- if (!mac->get_link_status) {
- ret_val = 0;
- goto out;
- }
+ if (!mac->get_link_status)
+ return 0;
/* First we want to see if the MII Status Register reports
* link. If so, then we want to get the current speed/duplex
base-commit: ca0e494af5edb59002665bf12871e94b4163a257
--
2.28.0.rc0
On 7/16/2020 07:49, Nathan Chancellor wrote:
> Clang warns:
>
Hello Nathan,
Thanks for tracking our code.Please, look at
https://patchwork.ozlabs.org/project/intel-wired-lan/patch/[email protected]/
- I hope this patch already address this Clang warns - please, let me know.
> drivers/net/ethernet/intel/igc/igc_mac.c:374:6: warning: variable 'link'
> is used uninitialized whenever 'if' condition is true
> [-Wsometimes-uninitialized]
> if (!mac->get_link_status) {
> ^~~~~~~~~~~~~~~~~~~~~
> drivers/net/ethernet/intel/igc/igc_mac.c:424:33: note: uninitialized use
> occurs here
> ret_val = igc_set_ltr_i225(hw, link);
> ^~~~
> drivers/net/ethernet/intel/igc/igc_mac.c:374:2: note: remove the 'if' if
> its condition is always false
> if (!mac->get_link_status) {
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/net/ethernet/intel/igc/igc_mac.c:367:11: note: initialize the
> variable 'link' to silence this warning
> bool link;
> ^
> = 0
> 1 warning generated.
>
> It is not wrong, link is only uninitialized after this through
> igc_phy_has_link. Presumably, if we skip the majority of this function
> when get_link_status is false, we should skip calling igc_set_ltr_i225
> as well. Just directly return 0 in this case, rather than bothering with
> adding another label or initializing link in the if statement.
>
> Fixes: 707abf069548 ("igc: Add initial LTR support")
> Link: https://github.com/ClangBuiltLinux/linux/issues/1095
> Signed-off-by: Nathan Chancellor <[email protected]>
> ---
> drivers/net/ethernet/intel/igc/igc_mac.c | 6 ++----
> 1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/igc/igc_mac.c b/drivers/net/ethernet/intel/igc/igc_mac.c
> index b47e7b0a6398..26e3c56a4a8b 100644
> --- a/drivers/net/ethernet/intel/igc/igc_mac.c
> +++ b/drivers/net/ethernet/intel/igc/igc_mac.c
> @@ -371,10 +371,8 @@ s32 igc_check_for_copper_link(struct igc_hw *hw)
> * get_link_status flag is set upon receiving a Link Status
> * Change or Rx Sequence Error interrupt.
> */
> - if (!mac->get_link_status) {
> - ret_val = 0;
> - goto out;
> - }
> + if (!mac->get_link_status)
> + return 0;
>
> /* First we want to see if the MII Status Register reports
> * link. If so, then we want to get the current speed/duplex
>
> base-commit: ca0e494af5edb59002665bf12871e94b4163a257
>
Thanks,
Sasha
On Thu, Jul 16, 2020 at 07:29:03PM +0300, Neftin, Sasha wrote:
> On 7/16/2020 07:49, Nathan Chancellor wrote:
> > Clang warns:
> >
> Hello Nathan,
> Thanks for tracking our code.Please, look at https://patchwork.ozlabs.org/project/intel-wired-lan/patch/[email protected]/
> - I hope this patch already address this Clang warns - please, let me know.
I have not explicitly tested it but it seems obvious that it will. Let's
go with that.
Cheers,
Nathan
> > drivers/net/ethernet/intel/igc/igc_mac.c:374:6: warning: variable 'link'
> > is used uninitialized whenever 'if' condition is true
> > [-Wsometimes-uninitialized]
> > if (!mac->get_link_status) {
> > ^~~~~~~~~~~~~~~~~~~~~
> > drivers/net/ethernet/intel/igc/igc_mac.c:424:33: note: uninitialized use
> > occurs here
> > ret_val = igc_set_ltr_i225(hw, link);
> > ^~~~
> > drivers/net/ethernet/intel/igc/igc_mac.c:374:2: note: remove the 'if' if
> > its condition is always false
> > if (!mac->get_link_status) {
> > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > drivers/net/ethernet/intel/igc/igc_mac.c:367:11: note: initialize the
> > variable 'link' to silence this warning
> > bool link;
> > ^
> > = 0
> > 1 warning generated.
> >
> > It is not wrong, link is only uninitialized after this through
> > igc_phy_has_link. Presumably, if we skip the majority of this function
> > when get_link_status is false, we should skip calling igc_set_ltr_i225
> > as well. Just directly return 0 in this case, rather than bothering with
> > adding another label or initializing link in the if statement.
> >
> > Fixes: 707abf069548 ("igc: Add initial LTR support")
> > Link: https://github.com/ClangBuiltLinux/linux/issues/1095
> > Signed-off-by: Nathan Chancellor <[email protected]>
> > ---
> > drivers/net/ethernet/intel/igc/igc_mac.c | 6 ++----
> > 1 file changed, 2 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/intel/igc/igc_mac.c b/drivers/net/ethernet/intel/igc/igc_mac.c
> > index b47e7b0a6398..26e3c56a4a8b 100644
> > --- a/drivers/net/ethernet/intel/igc/igc_mac.c
> > +++ b/drivers/net/ethernet/intel/igc/igc_mac.c
> > @@ -371,10 +371,8 @@ s32 igc_check_for_copper_link(struct igc_hw *hw)
> > * get_link_status flag is set upon receiving a Link Status
> > * Change or Rx Sequence Error interrupt.
> > */
> > - if (!mac->get_link_status) {
> > - ret_val = 0;
> > - goto out;
> > - }
> > + if (!mac->get_link_status)
> > + return 0;
> > /* First we want to see if the MII Status Register reports
> > * link. If so, then we want to get the current speed/duplex
> >
> > base-commit: ca0e494af5edb59002665bf12871e94b4163a257
> >
> Thanks,
> Sasha
On 7/17/2020 05:12, Nathan Chancellor wrote:
> On Thu, Jul 16, 2020 at 07:29:03PM +0300, Neftin, Sasha wrote:
>> On 7/16/2020 07:49, Nathan Chancellor wrote:
>>> Clang warns:
>>>
>> Hello Nathan,
>> Thanks for tracking our code.Please, look at https://patchwork.ozlabs.org/project/intel-wired-lan/patch/[email protected]/
>> - I hope this patch already address this Clang warns - please, let me know.
>
> I have not explicitly tested it but it seems obvious that it will. Let's
> go with that.
>
Good Nathan, let's go with my
https://patchwork.ozlabs.org/project/intel-wired-lan/patch/[email protected]/
and let me know if warning still generated.
Thanks,
Sasha
> Cheers,
> Nathan
>
>>> drivers/net/ethernet/intel/igc/igc_mac.c:374:6: warning: variable 'link'
>>> is used uninitialized whenever 'if' condition is true
>>> [-Wsometimes-uninitialized]
>>> if (!mac->get_link_status) {
>>> ^~~~~~~~~~~~~~~~~~~~~
>>> drivers/net/ethernet/intel/igc/igc_mac.c:424:33: note: uninitialized use
>>> occurs here
>>> ret_val = igc_set_ltr_i225(hw, link);
>>> ^~~~
>>> drivers/net/ethernet/intel/igc/igc_mac.c:374:2: note: remove the 'if' if
>>> its condition is always false
>>> if (!mac->get_link_status) {
>>> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>> drivers/net/ethernet/intel/igc/igc_mac.c:367:11: note: initialize the
>>> variable 'link' to silence this warning
>>> bool link;
>>> ^
>>> = 0
>>> 1 warning generated.
>>>
>>> It is not wrong, link is only uninitialized after this through
>>> igc_phy_has_link. Presumably, if we skip the majority of this function
>>> when get_link_status is false, we should skip calling igc_set_ltr_i225
>>> as well. Just directly return 0 in this case, rather than bothering with
>>> adding another label or initializing link in the if statement.
>>>
>>> Fixes: 707abf069548 ("igc: Add initial LTR support")
>>> Link: https://github.com/ClangBuiltLinux/linux/issues/1095
>>> Signed-off-by: Nathan Chancellor <[email protected]>
>>> ---
>>> drivers/net/ethernet/intel/igc/igc_mac.c | 6 ++----
>>> 1 file changed, 2 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/drivers/net/ethernet/intel/igc/igc_mac.c b/drivers/net/ethernet/intel/igc/igc_mac.c
>>> index b47e7b0a6398..26e3c56a4a8b 100644
>>> --- a/drivers/net/ethernet/intel/igc/igc_mac.c
>>> +++ b/drivers/net/ethernet/intel/igc/igc_mac.c
>>> @@ -371,10 +371,8 @@ s32 igc_check_for_copper_link(struct igc_hw *hw)
>>> * get_link_status flag is set upon receiving a Link Status
>>> * Change or Rx Sequence Error interrupt.
>>> */
>>> - if (!mac->get_link_status) {
>>> - ret_val = 0;
>>> - goto out;
>>> - }
>>> + if (!mac->get_link_status)
>>> + return 0;
>>> /* First we want to see if the MII Status Register reports
>>> * link. If so, then we want to get the current speed/duplex
>>>
>>> base-commit: ca0e494af5edb59002665bf12871e94b4163a257
>>>
>> Thanks,
>> Sasha