git: cba56bc3427d - main - igc: fix MAC address hash bit shift

The branch main has been updated by kbowling:

URL: https://cgit.FreeBSD.org/src/commit/?id=cba56bc3427db0bb4efc3d0117cda4bdc7717f98

commit cba56bc3427db0bb4efc3d0117cda4bdc7717f98
Author:     Aleksandr Loktionov <[email protected]>
AuthorDate: 2026-08-11 19:34:01 +0000
Commit:     Kevin Bowling <[email protected]>
CommitDate: 2026-08-11 20:59:32 +0000

    igc: fix MAC address hash bit shift
    
    DPDK commit message
    
    net/e1000/base: fix MAC address hash bit shift
    
    In e1000_hash_mc_addr_generic() the expression:
    
    "mc_addr[4] >> 8 - bit_shift", right shifting "mc_addr[4]"
    
    shift by more than 7 bits always yields zero, so hash becomes not so
    different. Add initialization with bit_shift = 1, and add a loop
    condition to ensure bit_shift will be always in [1..8] range.
    
    Fixes: af75078fece3 ("first public release")
    Cc: [email protected]
    
    Signed-off-by: Aleksandr Loktionov <[email protected]>
    Signed-off-by: Anatoly Burakov <[email protected]>
    Acked-by: Bruce Richardson <[email protected]>
    
    Obtained from:  DPDK (1749e662f6)
    MFC after:      2 weeks
---
 sys/dev/igc/igc_mac.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sys/dev/igc/igc_mac.c b/sys/dev/igc/igc_mac.c
index 6a00867c7a8e..2c32f0c7a606 100644
--- a/sys/dev/igc/igc_mac.c
+++ b/sys/dev/igc/igc_mac.c
@@ -301,7 +301,7 @@ int igc_rar_set_generic(struct igc_hw *hw, u8 *addr, u32 index)
 u32 igc_hash_mc_addr_generic(struct igc_hw *hw, u8 *mc_addr)
 {
 	u32 hash_value, hash_mask;
-	u8 bit_shift = 0;
+	u8 bit_shift = 1;
 
 	DEBUGFUNC("igc_hash_mc_addr_generic");
 
@@ -311,7 +311,7 @@ u32 igc_hash_mc_addr_generic(struct igc_hw *hw, u8 *mc_addr)
 	/* For a mc_filter_type of 0, bit_shift is the number of left-shifts
 	 * where 0xFF would still fall within the hash mask.
 	 */
-	while (hash_mask >> bit_shift != 0xFF)
+	while (bit_shift < 4 && hash_mask >> bit_shift != 0xFF)
 		bit_shift++;
 
 	/* The portion of the address that is used for the hash table