[PATCH net-next] octeontx2: cn10k: fix RX flowid TCAM mask handling

The RX flowid programming initializes the TCAM mask to all ones, but
then overwrites it when clearing the MAC DA mask bits. This results
in losing the intended initialization and may affect other match fields.

Update the code to clear the MAC DA bits using an AND operation, making
the handling of mask[0] consistent with mask[1], where the field-specific
bits are cleared after initializing the mask to ~0ULL.

Signed-off-by: Alok Tiwari <redacted>
---
 drivers/net/ethernet/marvell/octeontx2/nic/cn10k_macsec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/cn10k_macsec.c b/drivers/net/ethernet/marvell/octeontx2/nic/cn10k_macsec.c
index 4c7e0f345cb5..060c715ebad0 100644
--- a/drivers/net/ethernet/marvell/octeontx2/nic/cn10k_macsec.c
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/cn10k_macsec.c

@@ -328,7 +328,7 @@ static int cn10k_mcs_write_rx_flowid(struct otx2_nic *pfvf,
 
 	req->data[0] = FIELD_PREP(MCS_TCAM0_MAC_DA_MASK, mac_da);
 	req->mask[0] = ~0ULL;
-	req->mask[0] = ~MCS_TCAM0_MAC_DA_MASK;
+	req->mask[0] &= ~MCS_TCAM0_MAC_DA_MASK;
 
 	req->data[1] = FIELD_PREP(MCS_TCAM1_ETYPE_MASK, ETH_P_MACSEC);
 	req->mask[1] = ~0ULL;

-- 
2.50.1

On 2026-01-16 at 22:17:12, Alok Tiwari (alok.a.tiwari@oracle.com) wrote:

The RX flowid programming initializes the TCAM mask to all ones, but
then overwrites it when clearing the MAC DA mask bits. This results
in losing the intended initialization and may affect other match fields.

Update the code to clear the MAC DA bits using an AND operation, making
the handling of mask[0] consistent with mask[1], where the field-specific
bits are cleared after initializing the mask to ~0ULL.

Signed-off-by: Alok Tiwari <redacted>

This has no impact in functionality and it is better to be consistent with
mask[1]. Thanks for the change.

Reviewed-by: Subbaraya Sundeep <sbhatta@marvell.com>

On Fri, 16 Jan 2026 08:47:12 -0800 Alok Tiwari wrote:

The RX flowid programming initializes the TCAM mask to all ones, but
then overwrites it when clearing the MAC DA mask bits. This results
in losing the intended initialization and may affect other match fields.

Update the code to clear the MAC DA bits using an AND operation, making
the handling of mask[0] consistent with mask[1], where the field-specific
bits are cleared after initializing the mask to ~0ULL.

In the future - if the code exists in Linus's tree the fix must have 
a Fixes tag and target net.

Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski [off-list ref]:

On Fri, 16 Jan 2026 08:47:12 -0800 you wrote:

The RX flowid programming initializes the TCAM mask to all ones, but
then overwrites it when clearing the MAC DA mask bits. This results
in losing the intended initialization and may affect other match fields.

Update the code to clear the MAC DA bits using an AND operation, making
the handling of mask[0] consistent with mask[1], where the field-specific
bits are cleared after initializing the mask to ~0ULL.

[...]

Here is the summary with links:
  - [net-next] octeontx2: cn10k: fix RX flowid TCAM mask handling
    https://git.kernel.org/netdev/net/c/ab9b218a1521

You are awesome, thank you!
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