Am 29.01.2015 um 05:09 schrieb zhengyuwei@xxxxxx: > From: Yuwei Zheng <zhengyuwei@xxxxxx> > > 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> > > --- > drivers/net/wireless/ath/ath9k/hif_usb.c | 53 ++++++++++++++++++++++---- > drivers/net/wireless/ath/ath9k/hif_usb.h | 5 +++ > drivers/net/wireless/ath/ath9k/htc.h | 13 +++++++ > drivers/net/wireless/ath/ath9k/htc_drv_debug.c | 49 ++++++++++++++++++++++++ > drivers/net/wireless/ath/ath9k/htc_drv_txrx.c | 26 +++++++++++++ > 5 files changed, 139 insertions(+), 7 deletions(-) First of all, thank you for you work! :D Please run ./scripts/checkpatch.pl yourpatch_path i get: total: 139 errors, 12 warnings, 2 checks, 231 lines checked You use tasklet_hrtimer_start. So far i know, there is no this kind of hrtimer which is actually hidden behind this word on this SoC. Especially if requested value is any way in 1 millisecond range you probably can and should use normal priority tasklet. (correct me if i'm wrong) > diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c > index 8e7153b..febea5e 100644 > --- a/drivers/net/wireless/ath/ath9k/hif_usb.c > +++ b/drivers/net/wireless/ath/ath9k/hif_usb.c > @@ -658,7 +658,6 @@ 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 +666,18 @@ 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); > + ret = tasklet_hrtimer_start(&hif_dev->rx_submit_timer, > + ktime_set(0, atomic_read(&hif_dev->rx_urb_submit_delay)*1000), > + HRTIMER_MODE_REL); > + } 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 +823,37 @@ err: > return -ENOMEM; > } > > +static enum hrtimer_restart rx_urb_submit_timer_handler(struct hrtimer *me) > +{ > + struct tasklet_hrtimer *thr = container_of(me, struct tasklet_hrtimer, timer); > + struct hif_device_usb *hif_dev = container_of(thr, struct hif_device_usb, rx_submit_timer); > + struct urb *urb = NULL; > + struct sk_buff *skb = NULL; > + int ret; > + > + while (true) { > + urb = usb_get_from_anchor(&hif_dev->rx_delayed_submitted); > + if (urb != NULL) { > + skb = (struct sk_buff *)urb->context; > + ret = usb_submit_urb(urb, GFP_ATOMIC); > + if (ret != -EBUSY) { > + usb_unanchor_urb(urb); > + dev_kfree_skb_any(skb); > + urb->context = NULL; > + } > + } else { > + break; > + } > + } > + > + return HRTIMER_NORESTART; > +} > + > 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); > + tasklet_hrtimer_cancel(&hif_dev->rx_submit_timer); > } > > static int ath9k_hif_usb_alloc_rx_urbs(struct hif_device_usb *hif_dev) > @@ -830,6 +863,8 @@ 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 +906,10 @@ static int ath9k_hif_usb_alloc_rx_urbs(struct hif_device_usb *hif_dev) > usb_free_urb(urb); > } > > + /* add for flow control*/ > + atomic_set(&hif_dev->rx_urb_submit_delay, 0); > + tasklet_hrtimer_init(&hif_dev->rx_submit_timer, rx_urb_submit_timer_handler, CLOCK_MONOTONIC, HRTIMER_MODE_REL); > + > 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..56d6be8 100644 > --- a/drivers/net/wireless/ath/ath9k/hif_usb.h > +++ b/drivers/net/wireless/ath/ath9k/hif_usb.h > @@ -98,9 +98,14 @@ 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 tasklet_hrtimer rx_submit_timer;/* delayed submit hrtimer */ > + 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..453d0a8 100644 > --- a/drivers/net/wireless/ath/ath9k/htc.h > +++ b/drivers/net/wireless/ath/ath9k/htc.h > @@ -331,6 +331,10 @@ 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 TASKLETRX_STAT_INC(c) (hif_dev->htc_handle->drv_priv->debug.taskletrx_stats.c++) > +#define TASKLETRX_STAT_ADD(c, a) (hif_dev->htc_handle->drv_priv->debug.taskletrx_stats.c += a) > +#define TASKLETRX_STAT_SET(c, a) (hif_dev->htc_handle->drv_priv->debug.taskletrx_stats.c = a) > + > void ath9k_htc_err_stat_rx(struct ath9k_htc_priv *priv, > struct ath_rx_status *rs); > > @@ -352,11 +356,20 @@ struct ath_skbrx_stats { > u32 skb_dropped; > }; > > +struct ath_taskletrx_stats { > + u32 taskletrx_looptimes; > + u32 taskletrx_highwater; > + u32 taskletrx_lowwater; > + u32 taskletrx_watermark_triggered; > + u32 taskletrx_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_taskletrx_stats taskletrx_stats; > }; > > void ath9k_htc_get_et_strings(struct ieee80211_hw *hw, > diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_debug.c b/drivers/net/wireless/ath/ath9k/htc_drv_debug.c > index 8cef1ed..7c8322e 100644 > --- a/drivers/net/wireless/ath/ath9k/htc_drv_debug.c > +++ b/drivers/net/wireless/ath/ath9k/htc_drv_debug.c > @@ -286,6 +286,51 @@ static const struct file_operations fops_skb_rx = { > .llseek = default_llseek, > }; > > +static ssize_t read_file_tasklet_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 == NULL) > + return -ENOMEM; > + > + len += scnprintf(buf + len, size - len, > + "%20s : %10u\n", "Loop times", > + priv->debug.taskletrx_stats.taskletrx_looptimes); > + len += scnprintf(buf + len, size - len, > + "%20s : %10u\n", "High watermark", > + priv->debug.taskletrx_stats.taskletrx_highwater); > + len += scnprintf(buf + len, size - len, > + "%20s : %10u\n", "Low watermark", > + priv->debug.taskletrx_stats.taskletrx_lowwater); > + > + len += scnprintf(buf + len, size - len, > + "%20s : %10u\n", "WM triggered", > + priv->debug.taskletrx_stats.taskletrx_watermark_triggered); > + > + len += scnprintf(buf + len, size - len, > + "%20s : %10u\n", "URB delay", > + priv->debug.taskletrx_stats.taskletrx_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_tasklet_rx = { > + .read = read_file_tasklet_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 +563,11 @@ 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("tasklet_rx", S_IRUSR, priv->debug.debugfs_phy, > + priv, &fops_tasklet_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..f5e6217 100644 > --- a/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c > +++ b/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c > @@ -1061,7 +1061,28 @@ 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/4; > + unsigned int delay = 0; > + > + struct htc_target *htc = priv->htc; > + struct hif_device_usb *hif_dev = htc->hif_dev; > + > + TASKLETRX_STAT_SET(taskletrx_highwater, highwatermark); > + TASKLETRX_STAT_SET(taskletrx_lowwater, lowwatermark); > + > do { > + looptimes++; > + TASKLETRX_STAT_SET(taskletrx_looptimes, looptimes); > + if (looptimes > highwatermark) { > + delay = looptimes*10; > + atomic_set(&hif_dev->rx_urb_submit_delay, delay); > + TASKLETRX_STAT_INC(taskletrx_watermark_triggered); > + TASKLETRX_STAT_SET(taskletrx_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 +1093,11 @@ 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); > + TASKLETRX_STAT_SET(taskletrx_urb_submit_delay, 0); > + } > + > break; > } > > -- Regards, Oleksij
Attachment:
signature.asc
Description: OpenPGP digital signature