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Miller" , Eric Dumazet , Paolo Abeni , Simon Horman , Stanislav Fomichev , Antoine Tenart , Kuniyuki Iwashima , Yajun Deng , open list References: <20251107002510.1678369-1-florian.fainelli@broadcom.com> <20251107002510.1678369-2-florian.fainelli@broadcom.com> <20251110171036.733aa203@kernel.org> Content-Language: en-US, fr-FR From: Florian Fainelli Autocrypt: addr=florian.fainelli@broadcom.com; keydata= xsBNBFPAG8ABCAC3EO02urEwipgbUNJ1r6oI2Vr/+uE389lSEShN2PmL3MVnzhViSAtrYxeT M0Txqn1tOWoIc4QUl6Ggqf5KP6FoRkCrgMMTnUAINsINYXK+3OLe7HjP10h2jDRX4Ajs4Ghs JrZOBru6rH0YrgAhr6O5gG7NE1jhly+EsOa2MpwOiXO4DE/YKZGuVe6Bh87WqmILs9KvnNrQ PcycQnYKTVpqE95d4M824M5cuRB6D1GrYovCsjA9uxo22kPdOoQRAu5gBBn3AdtALFyQj9DQ KQuc39/i/Kt6XLZ/RsBc6qLs+p+JnEuPJngTSfWvzGjpx0nkwCMi4yBb+xk7Hki4kEslABEB AAHNMEZsb3JpYW4gRmFpbmVsbGkgPGZsb3JpYW4uZmFpbmVsbGlAYnJvYWRjb20uY29tPsLB IQQQAQgAywUCZWl41AUJI+Jo+hcKAAG/SMv+fS3xUQWa0NryPuoRGjsA3SAUAAAAAAAWAAFr ZXktdXNhZ2UtbWFza0BwZ3AuY29tjDAUgAAAAAAgAAdwcmVmZXJyZWQtZW1haWwtZW5jb2Rp bmdAcGdwLmNvbXBncG1pbWUICwkIBwMCAQoFF4AAAAAZGGxkYXA6Ly9rZXlzLmJyb2FkY29t Lm5ldAUbAwAAAAMWAgEFHgEAAAAEFQgJChYhBNXZKpfnkVze1+R8aIExtcQpvGagAAoJEIEx tcQpvGagWPEH/2l0DNr9QkTwJUxOoP9wgHfmVhqc0ZlDsBFv91I3BbhGKI5UATbipKNqG13Z TsBrJHcrnCqnTRS+8n9/myOF0ng2A4YT0EJnayzHugXm+hrkO5O9UEPJ8a+0553VqyoFhHqA zjxj8fUu1px5cbb4R9G4UAySqyeLLeqnYLCKb4+GklGSBGsLMYvLmIDNYlkhMdnnzsSUAS61 WJYW6jjnzMwuKJ0ZHv7xZvSHyhIsFRiYiEs44kiYjbUUMcXor/uLEuTIazGrE3MahuGdjpT2 IOjoMiTsbMc0yfhHp6G/2E769oDXMVxCCbMVpA+LUtVIQEA+8Zr6mX0Yk4nDS7OiBlvOwE0E U8AbwQEIAKxr71oqe+0+MYCc7WafWEcpQHFUwvYLcdBoOnmJPxDwDRpvU5LhqSPvk/yJdh9k 4xUDQu3rm1qIW2I9Puk5n/Jz/lZsqGw8T13DKyu8eMcvaA/irm9lX9El27DPHy/0qsxmxVmU pu9y9S+BmaMb2CM9IuyxMWEl9ruWFS2jAWh/R8CrdnL6+zLk60R7XGzmSJqF09vYNlJ6Bdbs MWDXkYWWP5Ub1ZJGNJQ4qT7g8IN0qXxzLQsmz6tbgLMEHYBGx80bBF8AkdThd6SLhreCN7Uh IR/5NXGqotAZao2xlDpJLuOMQtoH9WVNuuxQQZHVd8if+yp6yRJ5DAmIUt5CCPcAEQEAAcLB gQQYAQIBKwUCU8AbwgUbDAAAAMBdIAQZAQgABgUCU8AbwQAKCRCTYAaomC8PVQ0VCACWk3n+ obFABEp5Rg6Qvspi9kWXcwCcfZV41OIYWhXMoc57ssjCand5noZi8bKg0bxw4qsg+9cNgZ3P N/DFWcNKcAT3Z2/4fTnJqdJS//YcEhlr8uGs+ZWFcqAPbteFCM4dGDRruo69IrHfyyQGx16s CcFlrN8vD066RKevFepb/ml7eYEdN5SRALyEdQMKeCSf3mectdoECEqdF/MWpfWIYQ1hEfdm C2Kztm+h3Nkt9ZQLqc3wsPJZmbD9T0c9Rphfypgw/SfTf2/CHoYVkKqwUIzI59itl5Lze+R5 wDByhWHx2Ud2R7SudmT9XK1e0x7W7a5z11Q6vrzuED5nQvkhAAoJEIExtcQpvGagugcIAJd5 EYe6KM6Y6RvI6TvHp+QgbU5dxvjqSiSvam0Ms3QrLidCtantcGT2Wz/2PlbZqkoJxMQc40rb fXa4xQSvJYj0GWpadrDJUvUu3LEsunDCxdWrmbmwGRKqZraV2oG7YEddmDqOe0Xm/NxeSobc MIlnaE6V0U8f5zNHB7Y46yJjjYT/Ds1TJo3pvwevDWPvv6rdBeV07D9s43frUS6xYd1uFxHC 7dZYWJjZmyUf5evr1W1gCgwLXG0PEi9n3qmz1lelQ8lSocmvxBKtMbX/OKhAfuP/iIwnTsww 95A2SaPiQZA51NywV8OFgsN0ITl2PlZ4Tp9hHERDe6nQCsNI/Us= In-Reply-To: <20251110171036.733aa203@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-DetectorID-Processed: b00c1d49-9d2e-4205-b15f-d015386d3d5e On 11/10/25 17:10, Jakub Kicinski wrote: > On Thu, 6 Nov 2025 16:25:09 -0800 Florian Fainelli wrote: >> Development devices on a lab network might be subject to kernel panics >> and if they have pause frame generation enabled, once the kernel panics, >> the Ethernet controller stops being serviced. This can create a flood of >> pause frames that certain switches are unable to handle resulting a >> completle paralysis of the network because they broadcast to other >> stations on that same network segment. >> >> To accomodate for such situation introduce a >> /sys/class/net//disable_pause_on_panic knob which will disable >> Ethernet pause frame generation upon kernel panic. >> >> Note that device driver wishing to make use of that feature need to >> implement ethtool_ops::set_pauseparam_panic to specifically deal with >> that atomic context. > > Some basic review comments below (no promises if addressing those will > make me for one feel any warmer towards the concept). > >> Documentation/ABI/testing/sysfs-class-net | 16 +++++ >> include/linux/ethtool.h | 3 + >> include/linux/netdevice.h | 1 + >> net/core/net-sysfs.c | 39 +++++++++++ >> net/ethernet/Makefile | 3 +- >> net/ethernet/pause_panic.c | 79 +++++++++++++++++++++++ > > panic.c or shutdown.c is probably a slightly better name, > more likely we'd add more code in that. > >> 6 files changed, 140 insertions(+), 1 deletion(-) >> create mode 100644 net/ethernet/pause_panic.c >> >> diff --git a/Documentation/ABI/testing/sysfs-class-net b/Documentation/ABI/testing/sysfs-class-net >> index ebf21beba846..da0e4e862aca 100644 >> --- a/Documentation/ABI/testing/sysfs-class-net >> +++ b/Documentation/ABI/testing/sysfs-class-net >> @@ -352,3 +352,19 @@ Description: >> 0 threaded mode disabled for this dev >> 1 threaded mode enabled for this dev >> == ================================== >> + >> +What: /sys/class/net//disable_pause_on_panic >> +Date: Nov 2025 >> +KernelVersion: 6.20 >> +Contact: netdev@vger.kernel.org >> +Description: >> + Boolean value to control whether to disable pause frame >> + generation on panic. This is helpful in environments where >> + the link partner may incorrect respond to pause frames (e.g.: >> + improperly configured Ethernet switches) >> + >> + Possible values: >> + == ===================================================== >> + 0 do not disable pause frame generation on kernel panic >> + 1 disable pause frame generation on kernel panic >> + == ===================================================== > > please no sysfs for something as niche as this feature Would you prefer ethtool in that case? -- Florian