diff mbox series

[net,v2,1/1] net: stmmac: Fix zero-division error when disabling tc cbs

Message ID 20240918061422.1589662-1-khai.wen.tan@linux.intel.com (mailing list archive)
State Accepted
Commit 675faf5a14c14a2be0b870db30a70764df81e2df
Delegated to: Netdev Maintainers
Headers show
Series [net,v2,1/1] net: stmmac: Fix zero-division error when disabling tc cbs | expand

Checks

Context Check Description
netdev/series_format success Single patches do not need cover letters
netdev/tree_selection success Clearly marked for net
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 16 this patch: 16
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 11 of 11 maintainers
netdev/build_clang success Errors and warnings before: 16 this patch: 16
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 18 this patch: 18
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 7 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-09-19--09-00 (tests: 764)

Commit Message

KhaiWenTan Sept. 18, 2024, 6:14 a.m. UTC
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>
---
v2:
  - reflected code for better understanding
v1: https://patchwork.kernel.org/project/netdevbpf/patch/20240912015541.363600-1-khai.wen.tan@linux.intel.com/
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c | 1 +
 1 file changed, 1 insertion(+)

Comments

Simon Horman Sept. 18, 2024, 7:06 a.m. UTC | #1
On Wed, Sep 18, 2024 at 02:14:22PM +0800, KhaiWenTan wrote:
> 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>
> ---
> v2:
>   - reflected code for better understanding
> v1: https://patchwork.kernel.org/project/netdevbpf/patch/20240912015541.363600-1-khai.wen.tan@linux.intel.com/

Thanks for the update.

Reviewed-by: Simon Horman <horms@kernel.org>
patchwork-bot+netdevbpf@kernel.org Sept. 24, 2024, 9:50 a.m. UTC | #2
Hello:

This patch was applied to netdev/net.git (main)
by Paolo Abeni <pabeni@redhat.com>:

On Wed, 18 Sep 2024 14:14:22 +0800 you wrote:
> 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.
> 
> [...]

Here is the summary with links:
  - [net,v2,1/1] net: stmmac: Fix zero-division error when disabling tc cbs
    https://git.kernel.org/netdev/net/c/675faf5a14c1

You are awesome, thank you!
diff mbox series

Patch

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
index 832998bc020b..75ad2da1a37f 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
@@ -386,6 +386,7 @@  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 */