net: stmmac: Fix zero-division error when disabling tc cbs

BugLink: https://bugs.launchpad.net/bugs/2089884

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@vger.kernel.org>
Co-developed-by: Choong Yong Liang <yong.liang.choong@linux.intel.com>
Signed-off-by: Choong Yong Liang <yong.liang.choong@linux.intel.com>
Signed-off-by: KhaiWenTan <khai.wen.tan@linux.intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20240918061422.1589662-1-khai.wen.tan@linux.intel.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Koichiro Den <koichiro.den@canonical.com>
Signed-off-by: Roxana Nicolescu <roxana.nicolescu@canonical.com>

This commit is contained in:

KhaiWenTan

2024-09-18 14:14:22 +08:00

committed by

Mehmet Basaran

parent 0316b0b567

commit eee253f998

1 changed files with 1 additions and 0 deletions

									
										drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
									
		+1
		
												View File
												
				@@ -396,6 +396,7 @@ static int tc_setup_cbs(struct stmmac_priv *priv,

							return ret;

						priv->plat->tx_queues_cfg[queue].mode_to_use = MTL_QUEUE_DCB;

						return 0;

					}

					/* Final adjustments for HW */