diff options
Diffstat (limited to 'drivers/net/wireless/iwlwifi/iwl-rx.c')
| -rw-r--r-- | drivers/net/wireless/iwlwifi/iwl-rx.c | 136 |
1 files changed, 0 insertions, 136 deletions
diff --git a/drivers/net/wireless/iwlwifi/iwl-rx.c b/drivers/net/wireless/iwlwifi/iwl-rx.c index bd63b785f68c..05fd75fb59ac 100644 --- a/drivers/net/wireless/iwlwifi/iwl-rx.c +++ b/drivers/net/wireless/iwlwifi/iwl-rx.c @@ -41,142 +41,6 @@ #include "iwl-agn-calib.h" #include "iwl-agn.h" -/****************************************************************************** - * - * RX path functions - * - ******************************************************************************/ - -/* - * Rx theory of operation - * - * Driver allocates a circular buffer of Receive Buffer Descriptors (RBDs), - * each of which point to Receive Buffers to be filled by the NIC. These get - * used not only for Rx frames, but for any command response or notification - * from the NIC. The driver and NIC manage the Rx buffers by means - * of indexes into the circular buffer. - * - * Rx Queue Indexes - * The host/firmware share two index registers for managing the Rx buffers. - * - * The READ index maps to the first position that the firmware may be writing - * to -- the driver can read up to (but not including) this position and get - * good data. - * The READ index is managed by the firmware once the card is enabled. - * - * The WRITE index maps to the last position the driver has read from -- the - * position preceding WRITE is the last slot the firmware can place a packet. - * - * The queue is empty (no good data) if WRITE = READ - 1, and is full if - * WRITE = READ. - * - * During initialization, the host sets up the READ queue position to the first - * INDEX position, and WRITE to the last (READ - 1 wrapped) - * - * When the firmware places a packet in a buffer, it will advance the READ index - * and fire the RX interrupt. The driver can then query the READ index and - * process as many packets as possible, moving the WRITE index forward as it - * resets the Rx queue buffers with new memory. - * - * The management in the driver is as follows: - * + A list of pre-allocated SKBs is stored in iwl->rxq->rx_free. When - * iwl->rxq->free_count drops to or below RX_LOW_WATERMARK, work is scheduled - * to replenish the iwl->rxq->rx_free. - * + In iwl_rx_replenish (scheduled) if 'processed' != 'read' then the - * iwl->rxq is replenished and the READ INDEX is updated (updating the - * 'processed' and 'read' driver indexes as well) - * + A received packet is processed and handed to the kernel network stack, - * detached from the iwl->rxq. The driver 'processed' index is updated. - * + The Host/Firmware iwl->rxq is replenished at tasklet time from the rx_free - * list. If there are no allocated buffers in iwl->rxq->rx_free, the READ - * INDEX is not incremented and iwl->status(RX_STALLED) is set. If there - * were enough free buffers and RX_STALLED is set it is cleared. - * - * - * Driver sequence: - * - * iwl_rx_queue_alloc() Allocates rx_free - * iwl_rx_replenish() Replenishes rx_free list from rx_used, and calls - * iwl_rx_queue_restock - * iwl_rx_queue_restock() Moves available buffers from rx_free into Rx - * queue, updates firmware pointers, and updates - * the WRITE index. If insufficient rx_free buffers - * are available, schedules iwl_rx_replenish - * - * -- enable interrupts -- - * ISR - iwl_rx() Detach iwl_rx_mem_buffers from pool up to the - * READ INDEX, detaching the SKB from the pool. - * Moves the packet buffer from queue to rx_used. - * Calls iwl_rx_queue_restock to refill any empty - * slots. - * ... - * - */ - -/** - * iwl_rx_queue_space - Return number of free slots available in queue. - */ -int iwl_rx_queue_space(const struct iwl_rx_queue *q) -{ - int s = q->read - q->write; - if (s <= 0) - s += RX_QUEUE_SIZE; - /* keep some buffer to not confuse full and empty queue */ - s -= 2; - if (s < 0) - s = 0; - return s; -} - -/** - * iwl_rx_queue_update_write_ptr - Update the write pointer for the RX queue - */ -void iwl_rx_queue_update_write_ptr(struct iwl_priv *priv, struct iwl_rx_queue *q) -{ - unsigned long flags; - u32 reg; - - spin_lock_irqsave(&q->lock, flags); - - if (q->need_update == 0) - goto exit_unlock; - - if (priv->cfg->base_params->shadow_reg_enable) { - /* shadow register enabled */ - /* Device expects a multiple of 8 */ - q->write_actual = (q->write & ~0x7); - iwl_write32(priv, FH_RSCSR_CHNL0_WPTR, q->write_actual); - } else { - /* If power-saving is in use, make sure device is awake */ - if (test_bit(STATUS_POWER_PMI, &priv->status)) { - reg = iwl_read32(priv, CSR_UCODE_DRV_GP1); - - if (reg & CSR_UCODE_DRV_GP1_BIT_MAC_SLEEP) { - IWL_DEBUG_INFO(priv, - "Rx queue requesting wakeup," - " GP1 = 0x%x\n", reg); - iwl_set_bit(priv, CSR_GP_CNTRL, - CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ); - goto exit_unlock; - } - - q->write_actual = (q->write & ~0x7); - iwl_write_direct32(priv, FH_RSCSR_CHNL0_WPTR, - q->write_actual); - - /* Else device is assumed to be awake */ - } else { - /* Device expects a multiple of 8 */ - q->write_actual = (q->write & ~0x7); - iwl_write_direct32(priv, FH_RSCSR_CHNL0_WPTR, - q->write_actual); - } - } - q->need_update = 0; - - exit_unlock: - spin_unlock_irqrestore(&q->lock, flags); -} /****************************************************************************** * |