journal.md

• iwl_hwrate_to_plcp_idx

  • Let's see what is stored inside rate_n_flags and what calls iwl_hwrate_to_plcp_idx:

    • rs_rate_from_ucode_rate

      This function calls iwl_hwrate_to_plcp_idx passing ucode_rate as a argument.

      • What is ucode_rate?

        • iwl_mvm_rs_tx_status

          This function calls rs_rate_from_ucode_rate passing tx_resp_hwrate as the ucode_rate argument.

          • What is tx_resp_hwrate?

            It is set by this line:

            u32 tx_resp_hwrate = (uintptr_t)info->status.status_driver_data[1];

            • What is status_driver_data[1]?

              • In mvm/tx.c:iwl_mvm_rx_tx_cmd_single:

                info->status.status_driver_data[1] =
                        (void *)(uintptr_t)le32_to_cpu(tx_resp->initial_rate);

                • What is tx_resp->initial_rate?

                  struct iwl_mvm_tx_resp notifies that firmware is transmitting a packet.

                  The initial_rate member is described as

                  For non-agg: rate of the successful Tx. For agg: rate of the Tx of all the batch. RATE_MCS_*

                  In iwl_mvm_rx_tx_cmd_single the initial_rate comes from the data member of struct iwl_rx_packet.

                  • iwl_mvm_rx_tx_cmd

                    It is a function which calls either iwl_mvm_rx_tx_cmd_single or iwl_mvm_rx_tx_cmd_agg depending on the tx_resp->frame_count value.

                It looks like tx_resp is the data of a packet. (?)

              • In mvm/tx.c:iwl_mvm_tx_reclaim:

                ba_info->status.status_driver_data[1] = (void *)(uintptr_t)rate;

    • rs_pretty_print_rate

      It is a debug function. Skipping...