2010-11-23 18:47:36

by Nick Kossifidis

[permalink] [raw]
Subject: [PATCH 05/30] ath5k: Debug DMA timeouts

* Increase timeouts on ath5k_hw_stop_tx_dma and also wait for
tx queue to stop before checking for pending frames

* Add a new debug level to debug dma start/stop

Signed-off-by: Nick Kossifidis <[email protected]>
---
drivers/net/wireless/ath/ath5k/debug.c | 1 +
drivers/net/wireless/ath/ath5k/debug.h | 2 +
drivers/net/wireless/ath/ath5k/dma.c | 34 +++++++++++++++++++++++++++----
3 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/drivers/net/wireless/ath/ath5k/debug.c b/drivers/net/wireless/ath/ath5k/debug.c
index 7d785cb..5341dd2 100644
--- a/drivers/net/wireless/ath/ath5k/debug.c
+++ b/drivers/net/wireless/ath/ath5k/debug.c
@@ -312,6 +312,7 @@ static const struct {
{ ATH5K_DEBUG_DUMP_RX, "dumprx", "print received skb content" },
{ ATH5K_DEBUG_DUMP_TX, "dumptx", "print transmit skb content" },
{ ATH5K_DEBUG_DUMPBANDS, "dumpbands", "dump bands" },
+ { ATH5K_DEBUG_DMA, "dma", "dma start/stop" },
{ ATH5K_DEBUG_ANI, "ani", "adaptive noise immunity" },
{ ATH5K_DEBUG_DESC, "desc", "descriptor chains" },
{ ATH5K_DEBUG_ANY, "all", "show all debug levels" },
diff --git a/drivers/net/wireless/ath/ath5k/debug.h b/drivers/net/wireless/ath/ath5k/debug.h
index 236edbd..3e34428 100644
--- a/drivers/net/wireless/ath/ath5k/debug.h
+++ b/drivers/net/wireless/ath/ath5k/debug.h
@@ -95,6 +95,7 @@ struct ath5k_dbg_info {
* @ATH5K_DEBUG_DUMP_RX: print received skb content
* @ATH5K_DEBUG_DUMP_TX: print transmit skb content
* @ATH5K_DEBUG_DUMPBANDS: dump bands
+ * @ATH5K_DEBUG_DMA: debug dma start/stop
* @ATH5K_DEBUG_TRACE: trace function calls
* @ATH5K_DEBUG_DESC: descriptor setup
* @ATH5K_DEBUG_ANY: show at any debug level
@@ -118,6 +119,7 @@ enum ath5k_debug_level {
ATH5K_DEBUG_DUMP_RX = 0x00000100,
ATH5K_DEBUG_DUMP_TX = 0x00000200,
ATH5K_DEBUG_DUMPBANDS = 0x00000400,
+ ATH5K_DEBUG_DMA = 0x00000800,
ATH5K_DEBUG_ANI = 0x00002000,
ATH5K_DEBUG_DESC = 0x00004000,
ATH5K_DEBUG_ANY = 0xffffffff
diff --git a/drivers/net/wireless/ath/ath5k/dma.c b/drivers/net/wireless/ath/ath5k/dma.c
index ca0467e..e39c953 100644
--- a/drivers/net/wireless/ath/ath5k/dma.c
+++ b/drivers/net/wireless/ath/ath5k/dma.c
@@ -70,7 +70,11 @@ int ath5k_hw_stop_rx_dma(struct ath5k_hw *ah)
for (i = 1000; i > 0 &&
(ath5k_hw_reg_read(ah, AR5K_CR) & AR5K_CR_RXE) != 0;
i--)
- udelay(10);
+ udelay(100);
+
+ if (i)
+ ATH5K_DBG(ah->ah_sc, ATH5K_DEBUG_DMA,
+ "failed to stop RX DMA !\n");

return i ? 0 : -EBUSY;
}
@@ -217,7 +221,18 @@ int ath5k_hw_stop_tx_dma(struct ath5k_hw *ah, unsigned int queue)
*/
AR5K_REG_WRITE_Q(ah, AR5K_QCU_TXD, queue);

- /*Check for pending frames*/
+ /* Wait for queue to stop */
+ for (i = 1000; i > 0 &&
+ (AR5K_REG_READ_Q(ah, AR5K_QCU_TXE, queue) != 0);
+ i--)
+ udelay(100);
+
+ if (AR5K_REG_READ_Q(ah, AR5K_QCU_TXE, queue))
+ ATH5K_DBG(ah->ah_sc, ATH5K_DEBUG_DMA,
+ "queue %i didn't stop !\n", queue);
+
+ /* Check for pending frames */
+ i = 1000;
do {
pending = ath5k_hw_reg_read(ah,
AR5K_QUEUE_STATUS(queue)) &
@@ -248,12 +263,12 @@ int ath5k_hw_stop_tx_dma(struct ath5k_hw *ah, unsigned int queue)
AR5K_DIAG_SW_CHANNEL_IDLE_HIGH);

/* Wait a while and disable mechanism */
- udelay(200);
+ udelay(400);
AR5K_REG_DISABLE_BITS(ah, AR5K_QUIET_CTL1,
AR5K_QUIET_CTL1_QT_EN);

/* Re-check for pending frames */
- i = 40;
+ i = 100;
do {
pending = ath5k_hw_reg_read(ah,
AR5K_QUEUE_STATUS(queue)) &
@@ -263,12 +278,21 @@ int ath5k_hw_stop_tx_dma(struct ath5k_hw *ah, unsigned int queue)

AR5K_REG_DISABLE_BITS(ah, AR5K_DIAG_SW_5211,
AR5K_DIAG_SW_CHANNEL_IDLE_HIGH);
+
+ if (pending)
+ ATH5K_DBG(ah->ah_sc, ATH5K_DEBUG_DMA,
+ "quiet mechanism didn't work q:%i !\n",
+ queue);
}

/* Clear register */
ath5k_hw_reg_write(ah, 0, AR5K_QCU_TXD);
- if (pending)
+ if (pending) {
+ ATH5K_DBG(ah->ah_sc, ATH5K_DEBUG_DMA,
+ "tx dma didn't stop (q:%i, frm:%i) !\n",
+ queue, pending);
return -EBUSY;
+ }
}

/* TODO: Check for success on 5210 else return error */