Re: [PATCH v2] net/cxgbe: read firmware configuration file from filesystem

[Ferruh Yigit <ferruh.yigit@xilinx.com>]

On 5/16/2022 11:27 AM, Rahul Lakkireddy wrote:
> Add support to read firmware configuration file from
> /lib/firmware/cxgb4/ path in the filesystem. The firmware
> config file is used to enable or disable NIC features before
> firmware initialization to help retrieve better debug data to
> analyze firmware init failures. The config file can also
> be used to redistribute resources, like queues, TCAMs, etc.,
> from disabled physical functions (PFs) to main PF, before
> firmware init.

Hi Rahul,

Please find comments below.

Also can you please send a new version for both 4/5 and 5/5 (this patch) 
from original series?

> 
> Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
> ---
> v2:
> - Update cxgbe pmd doc about the firmware config file
> - Update commit message to explain more about firmware config file
> 
>   doc/guides/nics/cxgbe.rst               |  28 ++
>   drivers/net/cxgbe/base/t4fw_interface.h |   1 +
>   drivers/net/cxgbe/cxgbe_main.c          | 329 ++++++++++++++++--------
>   3 files changed, 245 insertions(+), 113 deletions(-)
> 
> diff --git a/doc/guides/nics/cxgbe.rst b/doc/guides/nics/cxgbe.rst
> index a1d30c488b..fc8a5751f1 100644
> --- a/doc/guides/nics/cxgbe.rst
> +++ b/doc/guides/nics/cxgbe.rst
> @@ -838,3 +838,31 @@ to configure the mtu of all the ports with a single command.
>   
>        testpmd> port stop all
>        testpmd> port config all max-pkt-len 9000
> +
> +Hardware Configuration and Debugging
> +------------------------------------
> +
> +Firmware Configuration File
> +~~~~~~~~~~~~~~~~~~~~~~~~~~~
> +
> +To enable or disable Chelsio NIC features before firmware initialization,
> +the Chelsio firmware configuration file can be placed in following
> +directory. The CXGBE PMD will search and pick up the firmware
> +configuration file during the Chelsio NIC probe, before initializing
> +the firmware.
> +

Does it worth to mention what happens if the FW config file doesn't 
exist? Or mention from FW config file load order, as you described in 
mail list, to understand the relation with 'cxgbtool'?

> +.. code-block:: console
> +
> +   cp <path_to_config_file>/t6-config.txt /lib/firmware/cxgb4/t6-config.txt
> +

There is also 't5-config.txt' in the code.

> +The firmware configuration file is mainly intended to be used to debug
> +firmware initialization failures. It can also be used to redistribute
> +NIC resources from disabled physical functions (PFs) to main PF before
> +initializing firmware.
> +
> +.. warning::
> +
> +   Note that the Chelsio firmware configuration file contains very low
> +   level details that is specific to the Chelsio NIC. Hence, the
> +   firmware configuration file must not be modified without expert
> +   guidance from Chelsio support team.

Will it be too much detail to document what config can be changed via 
this FW config?

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