From: Yuwei Zheng <yuweizheng@xxxxxxx> In the environment with heavy wifi traffic, set the ar9271 into monitor mode, will trigger a deadloop panic. The ath9k_hif_usb_rx_cb function excute on the interrupt context, and ath9k_rx_tasklet excute on the soft irq context. In other words, the ath9k_hif_usb_rx_cb have more chance to excute than ath9k_rx_tasklet. So in the worst condition, the rx.rxbuf receive list is always full, and the do {}while(true) loop will not be break. The kernel get a soft lockup panic. [59011.007210] BUG: soft lockup - CPU#0 stuck for 23s! [kworker/0:0:30609] [59011.030560] BUG: scheduling while atomic: kworker/0:0/30609/0x40010100 [59013.804486] BUG: scheduling while atomic: kworker/0:0/30609/0x40010100 [59013.858522] Kernel panic - not syncing: softlockup: hung tasks [59014.038891] Exception stack(0xdf4bbc38 to 0xdf4bbc80) [59014.046834] bc20: de57b950 60000113 [59014.059579] bc40: 00000000 bb32bb32 60000113 de57b948 de57b500 dc7bb440 df4bbcd0 00000000 [59014.072337] bc60: de57b950 60000113 df4bbcd0 df4bbc80 c04c259d c04c25a0 60000133 ffffffff [59014.085233] [<c04c28db>] (__irq_svc+0x3b/0x5c) from [<c04c25a0>] (_raw_spin_unlock_irqrestore+0xc/0x10) [59014.100437] [<c04c25a0>] (_raw_spin_unlock_irqrestore+0xc/0x10) from [<bf9c2089>] (ath9k_rx_tasklet+0x290/0x490 [ath9k_htc]) [59014.118267] [<bf9c2089>] (ath9k_rx_tasklet+0x290/0x490 [ath9k_htc]) from [<c0036d23>] (tasklet_action+0x3b/0x98) [59014.134132] [<c0036d23>] (tasklet_action+0x3b/0x98) from [<c0036709>] (__do_softirq+0x99/0x16c) [59014.147784] [<c0036709>] (__do_softirq+0x99/0x16c) from [<c00369f7>] (irq_exit+0x5b/0x5c) [59014.160653] [<c00369f7>] (irq_exit+0x5b/0x5c) from [<c000cfc3>] (handle_IRQ+0x37/0x78) [59014.173124] [<c000cfc3>] (handle_IRQ+0x37/0x78) from [<c00085df>] (omap3_intc_handle_irq+0x5f/0x68) [59014.187225] [<c00085df>] (omap3_intc_handle_irq+0x5f/0x68) from [<c04c28db>](__irq_svc+0x3b/0x5c) This bug can be see with low performance board, such as uniprocessor beagle bone board. Signed-off-by: Yuwei Zheng <zhengyuwei@xxxxxx> Signed-off-by: Yuwei Zheng <yuweizheng@xxxxxxx> --- drivers/net/wireless/ath/ath9k/hif_usb.c | 61 +++++++++++++++++++++++--- drivers/net/wireless/ath/ath9k/hif_usb.h | 6 +++ drivers/net/wireless/ath/ath9k/htc.h | 18 ++++++++ drivers/net/wireless/ath/ath9k/htc_drv_debug.c | 46 +++++++++++++++++++ drivers/net/wireless/ath/ath9k/htc_drv_txrx.c | 25 +++++++++++ 5 files changed, 149 insertions(+), 7 deletions(-) diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c index 8e7153b..718bbd6 100644 --- a/drivers/net/wireless/ath/ath9k/hif_usb.c +++ b/drivers/net/wireless/ath/ath9k/hif_usb.c @@ -640,6 +640,7 @@ static void ath9k_hif_usb_rx_cb(struct urb *urb) struct hif_device_usb *hif_dev = usb_get_intfdata(usb_ifnum_to_if(urb->dev, 0)); int ret; + int delay; if (!skb) return; @@ -658,7 +659,6 @@ static void ath9k_hif_usb_rx_cb(struct urb *urb) default: goto resubmit; } - if (likely(urb->actual_length != 0)) { skb_put(skb, urb->actual_length); ath9k_hif_usb_rx_stream(hif_dev, skb); @@ -667,12 +667,18 @@ static void ath9k_hif_usb_rx_cb(struct urb *urb) resubmit: skb_reset_tail_pointer(skb); skb_trim(skb, 0); - - usb_anchor_urb(urb, &hif_dev->rx_submitted); - ret = usb_submit_urb(urb, GFP_ATOMIC); - if (ret) { - usb_unanchor_urb(urb); - goto free; + if (atomic_read(&hif_dev->rx_urb_submit_delay) > 0) { + usb_anchor_urb(urb, &hif_dev->rx_delayed_submitted); + delay = atomic_read(&hif_dev->rx_urb_submit_delay); + schedule_delayed_work(&hif_dev->rx_submit_delayed_work, + usecs_to_jiffies(delay)); + } else { + usb_anchor_urb(urb, &hif_dev->rx_submitted); + ret = usb_submit_urb(urb, GFP_ATOMIC); + if (ret) { + usb_unanchor_urb(urb); + goto free; + } } return; @@ -818,9 +824,43 @@ err: return -ENOMEM; } +static void rx_urb_delayed_submit_handler(struct work_struct *work) +{ + struct hif_device_usb *hif_dev = + container_of(work, + struct hif_device_usb, + rx_submit_delayed_work.work); + + struct urb *urb = NULL; + struct sk_buff *skb = NULL; + int ret; + int loop_times = 0; + + while (true) { + loop_times++; + if (loop_times > (MAX_RX_URB_NUM)) + atomic_add(ARC_RX_STEP, &hif_dev->rx_urb_submit_delay); + + urb = usb_get_from_anchor(&hif_dev->rx_delayed_submitted); + if (urb) { + skb = (struct sk_buff *)urb->context; + ret = usb_submit_urb(urb, GFP_KERNEL); + if (ret != 0) { + usb_unanchor_urb(urb); + dev_kfree_skb_any(skb); + urb->context = NULL; + } + } else { + break; + } + } +} + static void ath9k_hif_usb_dealloc_rx_urbs(struct hif_device_usb *hif_dev) { usb_kill_anchored_urbs(&hif_dev->rx_submitted); + usb_kill_anchored_urbs(&hif_dev->rx_delayed_submitted); + flush_delayed_work(&hif_dev->rx_submit_delayed_work); } static int ath9k_hif_usb_alloc_rx_urbs(struct hif_device_usb *hif_dev) @@ -830,6 +870,8 @@ static int ath9k_hif_usb_alloc_rx_urbs(struct hif_device_usb *hif_dev) int i, ret; init_usb_anchor(&hif_dev->rx_submitted); + init_usb_anchor(&hif_dev->rx_delayed_submitted); + spin_lock_init(&hif_dev->rx_lock); for (i = 0; i < MAX_RX_URB_NUM; i++) { @@ -871,6 +913,11 @@ static int ath9k_hif_usb_alloc_rx_urbs(struct hif_device_usb *hif_dev) usb_free_urb(urb); } + /* add for adaptive rate control*/ + atomic_set(&hif_dev->rx_urb_submit_delay, 0); + INIT_DELAYED_WORK(&hif_dev->rx_submit_delayed_work, + rx_urb_delayed_submit_handler); + return 0; err_submit: diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.h b/drivers/net/wireless/ath/ath9k/hif_usb.h index 51496e7..2127e50 100644 --- a/drivers/net/wireless/ath/ath9k/hif_usb.h +++ b/drivers/net/wireless/ath/ath9k/hif_usb.h @@ -41,6 +41,7 @@ #define MAX_RX_URB_NUM 8 #define MAX_RX_BUF_SIZE 16384 #define MAX_PKT_NUM_IN_TRANSFER 10 +#define ARC_RX_STEP 100 /* 100us */ #define MAX_REG_OUT_URB_NUM 1 #define MAX_REG_IN_URB_NUM 64 @@ -98,9 +99,14 @@ struct hif_device_usb { struct hif_usb_tx tx; struct usb_anchor regout_submitted; struct usb_anchor rx_submitted; + struct usb_anchor rx_delayed_submitted; /* delayed submit anchor */ struct usb_anchor reg_in_submitted; struct usb_anchor mgmt_submitted; struct sk_buff *remain_skb; + + struct delayed_work rx_submit_delayed_work; + atomic_t rx_urb_submit_delay; /*us*/ + const char *fw_name; int rx_remain_len; int rx_pkt_len; diff --git a/drivers/net/wireless/ath/ath9k/htc.h b/drivers/net/wireless/ath/ath9k/htc.h index 9dde265..3061dfa 100644 --- a/drivers/net/wireless/ath/ath9k/htc.h +++ b/drivers/net/wireless/ath/ath9k/htc.h @@ -331,6 +331,13 @@ static inline struct ath9k_htc_tx_ctl *HTC_SKB_CB(struct sk_buff *skb) #define TX_QSTAT_INC(q) (priv->debug.tx_stats.queue_stats[q]++) +#define ARCRX_STAT_INC(c) \ + (hif_dev->htc_handle->drv_priv->debug.arcrx_stats.c++) +#define ARCRX_STAT_ADD(c, a) \ + (hif_dev->htc_handle->drv_priv->debug.arcrx_stats.c += a) +#define ARCRX_STAT_SET(c, a) \ + (hif_dev->htc_handle->drv_priv->debug.arcrx_stats.c = a) + void ath9k_htc_err_stat_rx(struct ath9k_htc_priv *priv, struct ath_rx_status *rs); @@ -352,11 +359,19 @@ struct ath_skbrx_stats { u32 skb_dropped; }; +struct ath_arcrx_stats { + u32 arcrx_highwater; + u32 arcrx_lowwater; + u32 arcrx_watermark_triggered; + u32 arcrx_urb_submit_delay; +}; + struct ath9k_debug { struct dentry *debugfs_phy; struct ath_tx_stats tx_stats; struct ath_rx_stats rx_stats; struct ath_skbrx_stats skbrx_stats; + struct ath_arcrx_stats arcrx_stats; }; void ath9k_htc_get_et_strings(struct ieee80211_hw *hw, @@ -377,6 +392,9 @@ void ath9k_htc_get_et_stats(struct ieee80211_hw *hw, #define TX_QSTAT_INC(c) do { } while (0) +#define ARCRX_STAT_INC(c) do {} while (0) +#define ARCRX_STAT_ADD(c, a) do {} while (0) +#define ARCRX_STAT_SET(c, a) do {} while (0) static inline void ath9k_htc_err_stat_rx(struct ath9k_htc_priv *priv, struct ath_rx_status *rs) { diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_debug.c b/drivers/net/wireless/ath/ath9k/htc_drv_debug.c index 8cef1ed..45cc79d 100644 --- a/drivers/net/wireless/ath/ath9k/htc_drv_debug.c +++ b/drivers/net/wireless/ath/ath9k/htc_drv_debug.c @@ -286,6 +286,48 @@ static const struct file_operations fops_skb_rx = { .llseek = default_llseek, }; +static ssize_t read_file_arc_rx(struct file *file, char __user *user_buf, + size_t count, loff_t *ppos) +{ + struct ath9k_htc_priv *priv = file->private_data; + char *buf; + unsigned int len = 0, size = 1500; + ssize_t retval = 0; + + buf = kzalloc(size, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + len += scnprintf(buf + len, size - len, + "%20s : %10u\n", "High watermark", + priv->debug.arcrx_stats.arcrx_highwater); + len += scnprintf(buf + len, size - len, + "%20s : %10u\n", "Low watermark", + priv->debug.arcrx_stats.arcrx_lowwater); + + len += scnprintf(buf + len, size - len, + "%20s : %10u\n", "WM triggered", + priv->debug.arcrx_stats.arcrx_watermark_triggered); + + len += scnprintf(buf + len, size - len, + "%20s : %10u\n", "URB delay", + priv->debug.arcrx_stats.arcrx_urb_submit_delay); + if (len > size) + len = size; + + retval = simple_read_from_buffer(user_buf, count, ppos, buf, len); + kfree(buf); + + return retval; +} + +static const struct file_operations fops_arc_rx = { + .read = read_file_arc_rx, + .open = simple_open, + .owner = THIS_MODULE, + .llseek = default_llseek, +}; + static ssize_t read_file_slot(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) { @@ -518,7 +560,11 @@ int ath9k_htc_init_debug(struct ath_hw *ah) debugfs_create_file("skb_rx", S_IRUSR, priv->debug.debugfs_phy, priv, &fops_skb_rx); + debugfs_create_file("arc_rx", S_IRUSR, priv->debug.debugfs_phy, + priv, &fops_arc_rx); + ath9k_cmn_debug_recv(priv->debug.debugfs_phy, &priv->debug.rx_stats); + ath9k_cmn_debug_phy_err(priv->debug.debugfs_phy, &priv->debug.rx_stats); debugfs_create_file("slot", S_IRUSR, priv->debug.debugfs_phy, diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c b/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c index a0f58e2..9d2dc33 100644 --- a/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c +++ b/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c @@ -1061,7 +1061,27 @@ void ath9k_rx_tasklet(unsigned long data) unsigned long flags; struct ieee80211_hdr *hdr; + /* add for adaptive flow control*/ + int looptimes = 0; + int highwatermark = ATH9K_HTC_RXBUF*3/4; + int lowwatermark = ATH9K_HTC_RXBUF/32; + unsigned int delay = 0; + + struct htc_target *htc = priv->htc; + struct hif_device_usb *hif_dev = htc->hif_dev; + + ARCRX_STAT_SET(arcrx_highwater, highwatermark); + ARCRX_STAT_SET(arcrx_lowwater, lowwatermark); + do { + looptimes++; + if (looptimes > highwatermark) { + delay = looptimes*ARC_RX_STEP; + atomic_set(&hif_dev->rx_urb_submit_delay, delay); + ARCRX_STAT_INC(arcrx_watermark_triggered); + ARCRX_STAT_SET(arcrx_urb_submit_delay, delay); + } + spin_lock_irqsave(&priv->rx.rxbuflock, flags); list_for_each_entry(tmp_buf, &priv->rx.rxbuf, list) { if (tmp_buf->in_process) { @@ -1072,6 +1092,11 @@ void ath9k_rx_tasklet(unsigned long data) if (rxbuf == NULL) { spin_unlock_irqrestore(&priv->rx.rxbuflock, flags); + if (looptimes < lowwatermark) { + atomic_set(&hif_dev->rx_urb_submit_delay, 0); + ARCRX_STAT_SET(arcrx_urb_submit_delay, 0); + } + break; } -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html