[PATCH] igb: zero hwtstamp by default

[PATCH] igb: zero hwtstamp by default

[trix]

From: Tom Rix <trix@redhat.com>

Clang static analysis reports this representative issue
igb_ptp.c:997:3: warning: The left operand of '+' is a
  garbage value
  ktime_add_ns(shhwtstamps.hwtstamp, adjust);
  ^            ~~~~~~~~~~~~~~~~~~~~

shhwtstamps.hwtstamp is set by a call to
igb_ptp_systim_to_hwtstamp().  In the switch-statement
for the hw type, the hwtstamp is zeroed for matches
but not the default case.  Move the memset out of
switch-statement.  This degarbages the default case
and reduces the size.

Some whitespace cleanup of empty lines

Signed-off-by: Tom Rix <trix@redhat.com>
---
 drivers/net/ethernet/intel/igb/igb_ptp.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/intel/igb/igb_ptp.c b/drivers/net/ethernet/intel/igb/igb_ptp.c
index 6580fcddb4be5..02fec948ce642 100644
--- a/drivers/net/ethernet/intel/igb/igb_ptp.c
+++ b/drivers/net/ethernet/intel/igb/igb_ptp.c
@@ -165,23 +165,21 @@ static void igb_ptp_systim_to_hwtstamp(struct igb_adapter *adapter,
 	unsigned long flags;
 	u64 ns;
 
+	memset(hwtstamps, 0, sizeof(*hwtstamps));
+
 	switch (adapter->hw.mac.type) {
 	case e1000_82576:
 	case e1000_82580:
 	case e1000_i354:
 	case e1000_i350:
 		spin_lock_irqsave(&adapter->tmreg_lock, flags);
-
 		ns = timecounter_cyc2time(&adapter->tc, systim);
-
 		spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
 
-		memset(hwtstamps, 0, sizeof(*hwtstamps));
 		hwtstamps->hwtstamp = ns_to_ktime(ns);
 		break;
 	case e1000_i210:
 	case e1000_i211:
-		memset(hwtstamps, 0, sizeof(*hwtstamps));
 		/* Upper 32 bits contain s, lower 32 bits contain ns. */
 		hwtstamps->hwtstamp = ktime_set(systim >> 32,
 						systim & 0xFFFFFFFF);
-- 
2.26.3

RE: [Intel-wired-lan] [PATCH] igb: zero hwtstamp by default

[G, GurucharanX]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of
> trix@redhat.com
> Sent: Sunday, March 13, 2022 8:32 PM
> To: Brandeburg, Jesse <jesse.brandeburg@intel.com>; Nguyen, Anthony L
> <anthony.l.nguyen@intel.com>; davem@davemloft.net; kuba@kernel.org;
> nathan@kernel.org; ndesaulniers@google.com
> Cc: netdev@vger.kernel.org; llvm@lists.linux.dev; intel-wired-
> lan@lists.osuosl.org; linux-kernel@vger.kernel.org; Tom Rix
> <trix@redhat.com>
> Subject: [Intel-wired-lan] [PATCH] igb: zero hwtstamp by default
> 
> From: Tom Rix <trix@redhat.com>
> 
> Clang static analysis reports this representative issue
> igb_ptp.c:997:3: warning: The left operand of '+' is a
>   garbage value
>   ktime_add_ns(shhwtstamps.hwtstamp, adjust);
>   ^            ~~~~~~~~~~~~~~~~~~~~
> 
> shhwtstamps.hwtstamp is set by a call to igb_ptp_systim_to_hwtstamp().  In
> the switch-statement for the hw type, the hwtstamp is zeroed for matches
> but not the default case.  Move the memset out of switch-statement.  This
> degarbages the default case and reduces the size.
> 
> Some whitespace cleanup of empty lines
> 
> Signed-off-by: Tom Rix <trix@redhat.com>
> ---
>  drivers/net/ethernet/intel/igb/igb_ptp.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 

Tested-by: Gurucharan <gurucharanx.g@intel.com> (A Contingent worker at Intel)