* [PATCH linux-next] e1000: Remove redundant statement
@ 2021-10-18 8:53 luo penghao
2021-10-20 9:25 ` Simon Horman
0 siblings, 1 reply; 4+ messages in thread
From: luo penghao @ 2021-10-18 8:53 UTC (permalink / raw)
To: Jesse Brandeburg
Cc: Tony Nguyen, David S . Miller, Jakub Kicinski, intel-wired-lan,
netdev, linux-kernel, luo penghao, Zeal Robot
This statement is redundant in the context, because there will be
an identical statement next. otherwise, the variable initialization
is actually unnecessary.
The clang_analyzer complains as follows:
drivers/net/ethernet/intel/e1000/e1000_ethtool.c:1218:2 warning:
Value stored to 'ctrl_reg' is never read.
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: luo penghao <luo.penghao@zte.com.cn>
---
drivers/net/ethernet/intel/e1000/e1000_ethtool.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/drivers/net/ethernet/intel/e1000/e1000_ethtool.c b/drivers/net/ethernet/intel/e1000/e1000_ethtool.c
index 0a57172..8951f2a 100644
--- a/drivers/net/ethernet/intel/e1000/e1000_ethtool.c
+++ b/drivers/net/ethernet/intel/e1000/e1000_ethtool.c
@@ -1215,8 +1215,6 @@ static int e1000_integrated_phy_loopback(struct e1000_adapter *adapter)
e1000_write_phy_reg(hw, PHY_CTRL, 0x8140);
}
- ctrl_reg = er32(CTRL);
-
/* force 1000, set loopback */
e1000_write_phy_reg(hw, PHY_CTRL, 0x4140);
--
2.15.2
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH linux-next] e1000: Remove redundant statement
2021-10-18 8:53 [PATCH linux-next] e1000: Remove redundant statement luo penghao
@ 2021-10-20 9:25 ` Simon Horman
2021-10-20 18:08 ` [Intel-wired-lan] " Jesse Brandeburg
0 siblings, 1 reply; 4+ messages in thread
From: Simon Horman @ 2021-10-20 9:25 UTC (permalink / raw)
To: luo penghao
Cc: Jesse Brandeburg, Tony Nguyen, David S . Miller, Jakub Kicinski,
intel-wired-lan, netdev, linux-kernel, luo penghao, Zeal Robot
On Mon, Oct 18, 2021 at 08:53:05AM +0000, luo penghao wrote:
nit: s/linux-next/net-next/ in subject
> This statement is redundant in the context, because there will be
> an identical statement next. otherwise, the variable initialization
> is actually unnecessary.
>
> The clang_analyzer complains as follows:
>
> drivers/net/ethernet/intel/e1000/e1000_ethtool.c:1218:2 warning:
>
> Value stored to 'ctrl_reg' is never read.
I agree this does seem to be the case.
> Reported-by: Zeal Robot <zealci@zte.com.cn>
> Signed-off-by: luo penghao <luo.penghao@zte.com.cn>
Reviewed-by: Simon Horman <horms@kernel.org>
> ---
> drivers/net/ethernet/intel/e1000/e1000_ethtool.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/e1000/e1000_ethtool.c b/drivers/net/ethernet/intel/e1000/e1000_ethtool.c
> index 0a57172..8951f2a 100644
> --- a/drivers/net/ethernet/intel/e1000/e1000_ethtool.c
> +++ b/drivers/net/ethernet/intel/e1000/e1000_ethtool.c
> @@ -1215,8 +1215,6 @@ static int e1000_integrated_phy_loopback(struct e1000_adapter *adapter)
> e1000_write_phy_reg(hw, PHY_CTRL, 0x8140);
> }
>
> - ctrl_reg = er32(CTRL);
> -
> /* force 1000, set loopback */
> e1000_write_phy_reg(hw, PHY_CTRL, 0x4140);
>
> --
> 2.15.2
>
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Intel-wired-lan] [PATCH linux-next] e1000: Remove redundant statement
2021-10-20 9:25 ` Simon Horman
@ 2021-10-20 18:08 ` Jesse Brandeburg
2021-10-21 7:09 ` Simon Horman
0 siblings, 1 reply; 4+ messages in thread
From: Jesse Brandeburg @ 2021-10-20 18:08 UTC (permalink / raw)
To: Simon Horman
Cc: luo penghao, NetDEV list, Zeal Robot, linux-kernel,
intel-wired-lan, Jakub Kicinski, luo penghao, David S . Miller
Apologies for the duplicates, mail from my intel account going out
through outlook.com is not being delivered.
On Wed, Oct 20, 2021 at 7:00 AM Simon Horman <horms@kernel.org> wrote:
> > Value stored to 'ctrl_reg' is never read.
>
> I agree this does seem to be the case.
>
> > Reported-by: Zeal Robot <zealci@zte.com.cn>
> > Signed-off-by: luo penghao <luo.penghao@zte.com.cn>
>
> Reviewed-by: Simon Horman <horms@kernel.org>
Thanks for the review, but (davem/kuba) please do not apply.
> > @@ -1215,8 +1215,6 @@ static int e1000_integrated_phy_loopback(struct e1000_adapter *adapter)
> > e1000_write_phy_reg(hw, PHY_CTRL, 0x8140);
> > }
> >
> > - ctrl_reg = er32(CTRL);
Thanks for your patch, but this change is not safe. you're removing a
read that could do two things. The first is that the read "flushes"
the write just above to PCI (it's a PCI barrier), and the second is
that the read can have some side effects.
If this change must be done, the code should be to remove the
assignment to ctrl_reg, but leave the read, so the line would just
look like:
er32(CTRL);
This will get rid of the warning and not change the flow from the
hardware perspective.
> > -
> > /* force 1000, set loopback */
> > e1000_write_phy_reg(hw, PHY_CTRL, 0x4140);
> >
Please do not apply this.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Intel-wired-lan] [PATCH linux-next] e1000: Remove redundant statement
2021-10-20 18:08 ` [Intel-wired-lan] " Jesse Brandeburg
@ 2021-10-21 7:09 ` Simon Horman
0 siblings, 0 replies; 4+ messages in thread
From: Simon Horman @ 2021-10-21 7:09 UTC (permalink / raw)
To: Jesse Brandeburg
Cc: luo penghao, NetDEV list, Zeal Robot, linux-kernel,
intel-wired-lan, Jakub Kicinski, luo penghao, David S . Miller
On Wed, Oct 20, 2021 at 11:08:11AM -0700, Jesse Brandeburg wrote:
> Apologies for the duplicates, mail from my intel account going out
> through outlook.com is not being delivered.
>
> On Wed, Oct 20, 2021 at 7:00 AM Simon Horman <horms@kernel.org> wrote:
>
> > > Value stored to 'ctrl_reg' is never read.
> >
> > I agree this does seem to be the case.
> >
> > > Reported-by: Zeal Robot <zealci@zte.com.cn>
> > > Signed-off-by: luo penghao <luo.penghao@zte.com.cn>
> >
> > Reviewed-by: Simon Horman <horms@kernel.org>
>
> Thanks for the review, but (davem/kuba) please do not apply.
Thanks, and sorry for misunderstanding the patch.
>
> > > @@ -1215,8 +1215,6 @@ static int e1000_integrated_phy_loopback(struct e1000_adapter *adapter)
> > > e1000_write_phy_reg(hw, PHY_CTRL, 0x8140);
> > > }
> > >
> > > - ctrl_reg = er32(CTRL);
>
> Thanks for your patch, but this change is not safe. you're removing a
> read that could do two things. The first is that the read "flushes"
> the write just above to PCI (it's a PCI barrier), and the second is
> that the read can have some side effects.
>
> If this change must be done, the code should be to remove the
> assignment to ctrl_reg, but leave the read, so the line would just
> look like:
> er32(CTRL);
>
> This will get rid of the warning and not change the flow from the
> hardware perspective.
>
> > > -
> > > /* force 1000, set loopback */
> > > e1000_write_phy_reg(hw, PHY_CTRL, 0x4140);
> > >
>
> Please do not apply this.
>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-10-21 7:09 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-10-18 8:53 [PATCH linux-next] e1000: Remove redundant statement luo penghao
2021-10-20 9:25 ` Simon Horman
2021-10-20 18:08 ` [Intel-wired-lan] " Jesse Brandeburg
2021-10-21 7:09 ` Simon Horman
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).