Re: [Intel-wired-lan] [PATCH] igc: return an error if the mac type is unknown in igc_ptp_systim_to_hwtstamp()

From: Neftin, Sasha
Date: Wed Jan 18 2023 - 00:25:27 EST


On 1/14/2023 16:04, Tom Rix wrote:
clang static analysis reports
drivers/net/ethernet/intel/igc/igc_ptp.c:673:3: warning: The left operand of
'+' is a garbage value [core.UndefinedBinaryOperatorResult]
ktime_add_ns(shhwtstamps.hwtstamp, adjust);
^ ~~~~~~~~~~~~~~~~~~~~

igc_ptp_systim_to_hwtstamp() silently returns without setting the hwtstamp
if the mac type is unknown. This should be treated as an error.

Fixes: 81b055205e8b ("igc: Add support for RX timestamping")
Signed-off-by: Tom Rix <trix@xxxxxxxxxx>
---
drivers/net/ethernet/intel/igc/igc_ptp.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_ptp.c b/drivers/net/ethernet/intel/igc/igc_ptp.c
index c34734d432e0..4e10ced736db 100644
--- a/drivers/net/ethernet/intel/igc/igc_ptp.c
+++ b/drivers/net/ethernet/intel/igc/igc_ptp.c
@@ -417,10 +417,12 @@ static int igc_ptp_verify_pin(struct ptp_clock_info *ptp, unsigned int pin,
*
* We need to convert the system time value stored in the RX/TXSTMP registers
* into a hwtstamp which can be used by the upper level timestamping functions.
+ *
+ * Returns 0 on success.
**/
-static void igc_ptp_systim_to_hwtstamp(struct igc_adapter *adapter,
- struct skb_shared_hwtstamps *hwtstamps,
- u64 systim)
+static int igc_ptp_systim_to_hwtstamp(struct igc_adapter *adapter,
+ struct skb_shared_hwtstamps *hwtstamps,
+ u64 systim)
{
switch (adapter->hw.mac.type) {
case igc_i225:
@@ -430,8 +432,9 @@ static void igc_ptp_systim_to_hwtstamp(struct igc_adapter *adapter,
systim & 0xFFFFFFFF);
break;
default:
- break;
+ return -EINVAL;
}
+ return 0;
}
/**
@@ -652,7 +655,8 @@ static void igc_ptp_tx_hwtstamp(struct igc_adapter *adapter)
regval = rd32(IGC_TXSTMPL);
regval |= (u64)rd32(IGC_TXSTMPH) << 32;
- igc_ptp_systim_to_hwtstamp(adapter, &shhwtstamps, regval);
+ if (igc_ptp_systim_to_hwtstamp(adapter, &shhwtstamps, regval))
+ return;
switch (adapter->link_speed) {
case SPEED_10:
Acked-by: Sasha Neftin <sasha.neftin@xxxxxxxxx>