lkml.org 
[lkml]   [2020]   [Apr]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 11/37] docs: networking: convert netif-msg.txt to ReST
Date
- add SPDX header;
- adjust title and chapter markups;
- mark lists as such;
- mark code blocks and literals as such;
- adjust identation, whitespaces and blank lines;
- add to networking/index.rst.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
Documentation/networking/index.rst | 1 +
Documentation/networking/netif-msg.rst | 95 ++++++++++++++++++++++++++
Documentation/networking/netif-msg.txt | 79 ---------------------
3 files changed, 96 insertions(+), 79 deletions(-)
create mode 100644 Documentation/networking/netif-msg.rst
delete mode 100644 Documentation/networking/netif-msg.txt

diff --git a/Documentation/networking/index.rst b/Documentation/networking/index.rst
index 1ae0cbef8c04..d98509f15363 100644
--- a/Documentation/networking/index.rst
+++ b/Documentation/networking/index.rst
@@ -84,6 +84,7 @@ Contents:
netdev-features
netdevices
netfilter-sysctl
+ netif-msg

.. only:: subproject and html

diff --git a/Documentation/networking/netif-msg.rst b/Documentation/networking/netif-msg.rst
new file mode 100644
index 000000000000..b20d265a734d
--- /dev/null
+++ b/Documentation/networking/netif-msg.rst
@@ -0,0 +1,95 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===============
+NETIF Msg Level
+===============
+
+The design of the network interface message level setting.
+
+History
+-------
+
+ The design of the debugging message interface was guided and
+ constrained by backwards compatibility previous practice. It is useful
+ to understand the history and evolution in order to understand current
+ practice and relate it to older driver source code.
+
+ From the beginning of Linux, each network device driver has had a local
+ integer variable that controls the debug message level. The message
+ level ranged from 0 to 7, and monotonically increased in verbosity.
+
+ The message level was not precisely defined past level 3, but were
+ always implemented within +-1 of the specified level. Drivers tended
+ to shed the more verbose level messages as they matured.
+
+ - 0 Minimal messages, only essential information on fatal errors.
+ - 1 Standard messages, initialization status. No run-time messages
+ - 2 Special media selection messages, generally timer-driver.
+ - 3 Interface starts and stops, including normal status messages
+ - 4 Tx and Rx frame error messages, and abnormal driver operation
+ - 5 Tx packet queue information, interrupt events.
+ - 6 Status on each completed Tx packet and received Rx packets
+ - 7 Initial contents of Tx and Rx packets
+
+ Initially this message level variable was uniquely named in each driver
+ e.g. "lance_debug", so that a kernel symbolic debugger could locate and
+ modify the setting. When kernel modules became common, the variables
+ were consistently renamed to "debug" and allowed to be set as a module
+ parameter.
+
+ This approach worked well. However there is always a demand for
+ additional features. Over the years the following emerged as
+ reasonable and easily implemented enhancements
+
+ - Using an ioctl() call to modify the level.
+ - Per-interface rather than per-driver message level setting.
+ - More selective control over the type of messages emitted.
+
+ The netif_msg recommendation adds these features with only a minor
+ complexity and code size increase.
+
+ The recommendation is the following points
+
+ - Retaining the per-driver integer variable "debug" as a module
+ parameter with a default level of '1'.
+
+ - Adding a per-interface private variable named "msg_enable". The
+ variable is a bit map rather than a level, and is initialized as::
+
+ 1 << debug
+
+ Or more precisely::
+
+ debug < 0 ? 0 : 1 << min(sizeof(int)-1, debug)
+
+ Messages should changes from::
+
+ if (debug > 1)
+ printk(MSG_DEBUG "%s: ...
+
+ to::
+
+ if (np->msg_enable & NETIF_MSG_LINK)
+ printk(MSG_DEBUG "%s: ...
+
+
+The set of message levels is named
+
+
+ ========= =================== ============
+ Old level Name Bit position
+ ========= =================== ============
+ 0 NETIF_MSG_DRV 0x0001
+ 1 NETIF_MSG_PROBE 0x0002
+ 2 NETIF_MSG_LINK 0x0004
+ 2 NETIF_MSG_TIMER 0x0004
+ 3 NETIF_MSG_IFDOWN 0x0008
+ 3 NETIF_MSG_IFUP 0x0008
+ 4 NETIF_MSG_RX_ERR 0x0010
+ 4 NETIF_MSG_TX_ERR 0x0010
+ 5 NETIF_MSG_TX_QUEUED 0x0020
+ 5 NETIF_MSG_INTR 0x0020
+ 6 NETIF_MSG_TX_DONE 0x0040
+ 6 NETIF_MSG_RX_STATUS 0x0040
+ 7 NETIF_MSG_PKTDATA 0x0080
+ ========= =================== ============
diff --git a/Documentation/networking/netif-msg.txt b/Documentation/networking/netif-msg.txt
deleted file mode 100644
index c967ddb90d0b..000000000000
--- a/Documentation/networking/netif-msg.txt
+++ /dev/null
@@ -1,79 +0,0 @@
-
-________________
-NETIF Msg Level
-
-The design of the network interface message level setting.
-
-History
-
- The design of the debugging message interface was guided and
- constrained by backwards compatibility previous practice. It is useful
- to understand the history and evolution in order to understand current
- practice and relate it to older driver source code.
-
- From the beginning of Linux, each network device driver has had a local
- integer variable that controls the debug message level. The message
- level ranged from 0 to 7, and monotonically increased in verbosity.
-
- The message level was not precisely defined past level 3, but were
- always implemented within +-1 of the specified level. Drivers tended
- to shed the more verbose level messages as they matured.
- 0 Minimal messages, only essential information on fatal errors.
- 1 Standard messages, initialization status. No run-time messages
- 2 Special media selection messages, generally timer-driver.
- 3 Interface starts and stops, including normal status messages
- 4 Tx and Rx frame error messages, and abnormal driver operation
- 5 Tx packet queue information, interrupt events.
- 6 Status on each completed Tx packet and received Rx packets
- 7 Initial contents of Tx and Rx packets
-
- Initially this message level variable was uniquely named in each driver
- e.g. "lance_debug", so that a kernel symbolic debugger could locate and
- modify the setting. When kernel modules became common, the variables
- were consistently renamed to "debug" and allowed to be set as a module
- parameter.
-
- This approach worked well. However there is always a demand for
- additional features. Over the years the following emerged as
- reasonable and easily implemented enhancements
- Using an ioctl() call to modify the level.
- Per-interface rather than per-driver message level setting.
- More selective control over the type of messages emitted.
-
- The netif_msg recommendation adds these features with only a minor
- complexity and code size increase.
-
- The recommendation is the following points
- Retaining the per-driver integer variable "debug" as a module
- parameter with a default level of '1'.
-
- Adding a per-interface private variable named "msg_enable". The
- variable is a bit map rather than a level, and is initialized as
- 1 << debug
- Or more precisely
- debug < 0 ? 0 : 1 << min(sizeof(int)-1, debug)
-
- Messages should changes from
- if (debug > 1)
- printk(MSG_DEBUG "%s: ...
- to
- if (np->msg_enable & NETIF_MSG_LINK)
- printk(MSG_DEBUG "%s: ...
-
-
-The set of message levels is named
- Old level Name Bit position
- 0 NETIF_MSG_DRV 0x0001
- 1 NETIF_MSG_PROBE 0x0002
- 2 NETIF_MSG_LINK 0x0004
- 2 NETIF_MSG_TIMER 0x0004
- 3 NETIF_MSG_IFDOWN 0x0008
- 3 NETIF_MSG_IFUP 0x0008
- 4 NETIF_MSG_RX_ERR 0x0010
- 4 NETIF_MSG_TX_ERR 0x0010
- 5 NETIF_MSG_TX_QUEUED 0x0020
- 5 NETIF_MSG_INTR 0x0020
- 6 NETIF_MSG_TX_DONE 0x0040
- 6 NETIF_MSG_RX_STATUS 0x0040
- 7 NETIF_MSG_PKTDATA 0x0080
-
--
2.25.4
\
 
 \ /
  Last update: 2020-04-30 18:10    [W:0.329 / U:0.012 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site