From: KhaiWenTan <khai.wen.tan@xxxxxxxxxxxxxxx>
commit 675faf5a14c14a2be0b870db30a70764df81e2df upstream.
The commit b8c43360f6e4 ("net: stmmac: No need to calculate speed divider
when offload is disabled") allows the "port_transmit_rate_kbps" to be
set to a value of 0, which is then passed to the "div_s64" function when
tc-cbs is disabled. This leads to a zero-division error.
When tc-cbs is disabled, the idleslope, sendslope, and credit values the
credit values are not required to be configured. Therefore, adding a return
statement after setting the txQ mode to DCB when tc-cbs is disabled would
prevent a zero-division error.
Fixes: b8c43360f6e4 ("net: stmmac: No need to calculate speed divider when offload is disabled")
Cc: <stable@xxxxxxxxxxxxxxx>
Co-developed-by: Choong Yong Liang <yong.liang.choong@xxxxxxxxxxxxxxx>
Signed-off-by: Choong Yong Liang <yong.liang.choong@xxxxxxxxxxxxxxx>
Signed-off-by: KhaiWenTan <khai.wen.tan@xxxxxxxxxxxxxxx>
Reviewed-by: Simon Horman <horms@xxxxxxxxxx>
Link: https://patch.msgid.link/20240918061422.1589662-1-khai.wen.tan@xxxxxxxxxxxxxxx
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c | 1 +
1 file changed, 1 insertion(+)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
@@ -396,6 +396,7 @@ static int tc_setup_cbs(struct stmmac_pr
return ret;
priv->plat->tx_queues_cfg[queue].mode_to_use = MTL_QUEUE_DCB;
+ return 0;
}
/* Final adjustments for HW */
Patches currently in stable-queue which might be from khai.wen.tan@xxxxxxxxxxxxxxx are
queue-6.10/net-stmmac-fix-zero-division-error-when-disabling-tc-cbs.patch
