diff options
Diffstat (limited to 'drivers/net/wireless/ath/ath9k/mac.c')
| -rw-r--r-- | drivers/net/wireless/ath/ath9k/mac.c | 29 |
1 files changed, 27 insertions, 2 deletions
diff --git a/drivers/net/wireless/ath/ath9k/mac.c b/drivers/net/wireless/ath/ath9k/mac.c index 09ed441eb6ba..71b84d91dcff 100644 --- a/drivers/net/wireless/ath/ath9k/mac.c +++ b/drivers/net/wireless/ath/ath9k/mac.c @@ -70,12 +70,37 @@ u32 ath9k_hw_numtxpending(struct ath_hw *ah, u32 q) } EXPORT_SYMBOL(ath9k_hw_numtxpending); +/** + * ath9k_hw_updatetxtriglevel - adjusts the frame trigger level + * + * @ah: atheros hardware struct + * @bIncTrigLevel: whether or not the frame trigger level should be updated + * + * The frame trigger level specifies the minimum number of bytes, + * in units of 64 bytes, that must be DMA'ed into the PCU TX FIFO + * before the PCU will initiate sending the frame on the air. This can + * mean we initiate transmit before a full frame is on the PCU TX FIFO. + * Resets to 0x1 (meaning 64 bytes or a full frame, whichever occurs + * first) + * + * Caution must be taken to ensure to set the frame trigger level based + * on the DMA request size. For example if the DMA request size is set to + * 128 bytes the trigger level cannot exceed 6 * 64 = 384. This is because + * there need to be enough space in the tx FIFO for the requested transfer + * size. Hence the tx FIFO will stop with 512 - 128 = 384 bytes. If we set + * the threshold to a value beyond 6, then the transmit will hang. + * + * Current dual stream devices have a PCU TX FIFO size of 8 KB. + * Current single stream devices have a PCU TX FIFO size of 4 KB, however, + * there is a hardware issue which forces us to use 2 KB instead so the + * frame trigger level must not exceed 2 KB for these chipsets. + */ bool ath9k_hw_updatetxtriglevel(struct ath_hw *ah, bool bIncTrigLevel) { u32 txcfg, curLevel, newLevel; enum ath9k_int omask; - if (ah->tx_trig_level >= MAX_TX_FIFO_THRESHOLD) + if (ah->tx_trig_level >= ah->config.max_txtrig_level) return false; omask = ath9k_hw_set_interrupts(ah, ah->mask_reg & ~ATH9K_INT_GLOBAL); @@ -84,7 +109,7 @@ bool ath9k_hw_updatetxtriglevel(struct ath_hw *ah, bool bIncTrigLevel) curLevel = MS(txcfg, AR_FTRIG); newLevel = curLevel; if (bIncTrigLevel) { - if (curLevel < MAX_TX_FIFO_THRESHOLD) + if (curLevel < ah->config.max_txtrig_level) newLevel++; } else if (curLevel > MIN_TX_FIFO_THRESHOLD) newLevel--; |