Re: [PATCH net-next v3 5/5] ice: add documentation for FW logging

[Paul M Stillwell Jr <paul.m.stillwell.jr@intel.com>]

On 8/16/2023 3:43 PM, Randy Dunlap wrote:
> 
> 
> On 8/15/23 09:57, Tony Nguyen wrote:
>> From: Paul M Stillwell Jr <paul.m.stillwell.jr@intel.com>
>>
>> Add documentation for FW logging in
>> Documentation/networking/device-drivers/ethernet/intel/ice.rst
>>
>> Signed-off-by: Paul M Stillwell Jr <paul.m.stillwell.jr@intel.com>
>> Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
>> ---
>>   .../device_drivers/ethernet/intel/ice.rst     | 117 ++++++++++++++++++
>>   1 file changed, 117 insertions(+)
>>
>> diff --git a/Documentation/networking/device_drivers/ethernet/intel/ice.rst b/Documentation/networking/device_drivers/ethernet/intel/ice.rst
>> index e4d065c55ea8..3ddef911faaa 100644
>> --- a/Documentation/networking/device_drivers/ethernet/intel/ice.rst
>> +++ b/Documentation/networking/device_drivers/ethernet/intel/ice.rst
>> @@ -895,6 +895,123 @@ driver writes raw bytes by the GNSS object to the receiver through i2c. Please
>>   refer to the hardware GNSS module documentation for configuration details.
>>   
>>   
>> +Firmware (FW) logging
>> +---------------------
>> +The driver supports FW logging via the debugfs interface on PF 0 only. In order
>> +for FW logging to work, the NVM must support it. The 'fwlog' file will only get
>> +created in the ice debugfs directory if the NVM supports FW logging.
>> +
>> +Module configuration
>> +~~~~~~~~~~~~~~~~~~~~
>> +To see the status of FW logging then read the 'fwlog/modules' file like this::
> 
>                       of FW logging, read
> 

Fixed

>> +
>> +  # cat /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/modules
>> +
>> +To configure FW logging then write to the 'fwlog/modules' file like this::
> 
>                  FW logging, write to
> 

Fixed

>> +
>> +  # echo <fwlog_event> <fwlog_level> > /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/modules
>> +
>> +where
>> +
>> +* fwlog_level is a name as described below. Each level includes the
>> +  messages from the previous/lower level
>> +
>> +      * NONE
> 
> Should NONE be aligned with the entries below?
> Ah, they are aligned in the source file, but NONE uses a space after the '*'
> while the others use a TAB after the '*'.
> 

Good catch, fixed

>> +      *	ERROR
>> +      *	WARNING
>> +      *	NORMAL
>> +      *	VERBOSE
>> +
>> +* fwlog_event is a name that represents the module to receive events for. The
>> +  module names are
>> +
>> +      *	GENERAL
>> +      *	CTRL
>> +      *	LINK
>> +      *	LINK_TOPO
>> +      *	DNL
>> +      *	I2C
>> +      *	SDP
>> +      *	MDIO
>> +      *	ADMINQ
>> +      *	HDMA
>> +      *	LLDP
>> +      *	DCBX
>> +      *	DCB
>> +      *	XLR
>> +      *	NVM
>> +      *	AUTH
>> +      *	VPD
>> +      *	IOSF
>> +      *	PARSER
>> +      *	SW
>> +      *	SCHEDULER
>> +      *	TXQ
>> +      *	RSVD
>> +      *	POST
>> +      *	WATCHDOG
>> +      *	TASK_DISPATCH
>> +      *	MNG
>> +      *	SYNCE
>> +      *	HEALTH
>> +      *	TSDRV
>> +      *	PFREG
>> +      *	MDLVER
>> +      *	ALL
>> +
>> +The name ALL is special and specifies setting all of the modules to the
>> +specified fwlog_level.
>> +
>> +Example usage to configure the modules::
>> +
>> +  # echo LINK VERBOSE > /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/modules
>> +
>> +Enabling FW log
>> +~~~~~~~~~~~~~~~
>> +Once the desired modules are configured the user will enable the logging. To do
> 
>                                             the user enables logging. To do
> 

Fixed

>> +this the user can write a 1 (enable) or 0 (disable) to 'fwlog/enable'. An
>> +example is::
>> +
>> +  # echo 1 > /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/enable
>> +
>> +Retrieving FW log data
>> +~~~~~~~~~~~~~~~~~~~~~~
>> +The FW log data can be retrieved by reading from 'fwlog/data'. The user can
>> +write to 'fwlog/data' to clear the data. The data can only be cleared when FW
>> +logging is disabled. The FW log data is a binary file that is sent to Intel and
>> +used to help debug user issues.
>> +
>> +An example to read the data is::
>> +
>> +  # cat /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/data > fwlog.bin
>> +
>> +An example to clear the data is::
>> +
>> +  # echo 0 > /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/data
>> +
>> +Changing how often the log events are sent to the driver
>> +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> +The driver receives FW log data from the Admin Receive Queue (ARQ). The
>> +frequency that the FW sends the ARQ events can be configured by writing to
>> +'fwlog/resolution'. The range is 1-128 (1 means push every log message, 128
>> +means push only when the max AQ command buffer is full). The suggested value is
>> +10. The user can see what the value is configured to by reading
>> +'fwlog/resolution'. An example to set the value is::
>> +
>> +  # echo 50 > /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/resolution
>> +
>> +Configuring the number of buffers used to store FW log data
>> +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> +The driver stores FW log data in a ring within the driver. The default size of
>> +the ring is 256 4K buffers. Some use cases may require more or less data so
>> +the user can change the number of buffers that are allocated for FW log data.
>> +To change the number of buffers write to 'fwlog/nr_buffs'. The value must be a
>> +power of two and between the values 64-512. FW logging must be disabled to
> 
> or
> The value must be one of: 64, 128, 256, or 512.
> 

Changed

>> +change the value. An example of changing the value is::
>> +
>> +  # echo 128 > /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/nr_buffs
>> +
>> +
>>   Performance Optimization
>>   ========================
>>   Driver defaults are meant to fit a wide variety of workloads, but if further