Re: [PATCH] ath9k_htc: add adaptive usb receive flow control to repair soft lockup with monitor mode

From: Oleksij Rempel
Date: Mon Feb 09 2015 - 04:16:54 EST


Am 09.02.2015 um 08:20 schrieb Yuwei Zheng:
>
> On ä, 2015-02-06 at 23:24 +0100, Oleksij Rempel wrote:
>> formatting of this patch is still badly broken.
>> ./scripts/checkpatch.pl ~/Downloads/patch.eml
>> ....
>> ERROR: DOS line endings
>> #442: FILE: drivers/net/wireless/ath/ath9k/htc_drv_txrx.c:1170:
>> +^I^IAURFC_STAT_SET(aurfc_submit_delay, delay);^M$
>>
>> total: 195 errors, 6 warnings, 1 checks, 310 lines checked
>
>
> Don't save the email as microsoft eml format. The mail tool may
> translate it to DOS line endings if you save it as eml format.
>
> I have tested the patch and save it with Evolution as mobox format.
> The check result is
>
> total: 0 errors, 0 warnings, 1 checks, 310 lines checked

You right!

thank you for the tip.


>>
>> Am 06.02.2015 um 11:46 schrieb yuweizheng@xxxxxxx:
>>> 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 <yuweizheng@xxxxxxx>
>>>
>>> ---
>>> drivers/net/wireless/ath/ath9k/hif_usb.c | 74 +++++++++++++++++++++++---
>>> drivers/net/wireless/ath/ath9k/hif_usb.h | 9 ++++
>>> drivers/net/wireless/ath/ath9k/htc.h | 19 +++++++
>>> drivers/net/wireless/ath/ath9k/htc_drv_debug.c | 53 ++++++++++++++++++
>>> drivers/net/wireless/ath/ath9k/htc_drv_txrx.c | 44 +++++++++++++++
>>> 5 files changed, 192 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..90ee568 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 +667,22 @@ 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;
>>> + spin_lock(&hif_dev->aurfc_lock);
>>> + if (atomic_read(&hif_dev->aurfc_submit_delay) > 0 &&
>>> + hif_dev->aurfc_active == 1) {
>>> + usb_anchor_urb(urb, &hif_dev->rx_delayed_submitted);
>>> + delay = atomic_read(&hif_dev->aurfc_submit_delay);
>>> + schedule_delayed_work(&hif_dev->aurfc_delayed_work,
>>> + msecs_to_jiffies(delay));
>>> + spin_unlock(&hif_dev->aurfc_lock);
>>> + } else {
>>> + spin_unlock(&hif_dev->aurfc_lock);
>>> + 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 +828,50 @@ err:
>>> return -ENOMEM;
>>> }
>>>
>>> +static void aurfc_submit_handler(struct work_struct *work)
>>> +{
>>> + struct hif_device_usb *hif_dev =
>>> + container_of(work,
>>> + struct hif_device_usb,
>>> + aurfc_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(AURFC_STEP,
>>> + &hif_dev->aurfc_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)
>>> {
>>> + unsigned long flags;
>>> +
>>> + spin_lock_irqsave(&hif_dev->aurfc_lock, flags);
>>> + hif_dev->aurfc_active = 0;
>>> + mod_delayed_work(system_wq, &hif_dev->aurfc_delayed_work, 0);
>>> + spin_unlock_irqrestore(&hif_dev->aurfc_lock, flags);
>>> usb_kill_anchored_urbs(&hif_dev->rx_submitted);
>>> + usb_kill_anchored_urbs(&hif_dev->rx_delayed_submitted);
>>> }
>>>
>>> static int ath9k_hif_usb_alloc_rx_urbs(struct hif_device_usb *hif_dev)
>>> @@ -830,8 +881,17 @@ 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);
>>>
>>> + /* add for adaptive usb receive control*/
>>> + atomic_set(&hif_dev->aurfc_submit_delay, 0);
>>> + INIT_DELAYED_WORK(&hif_dev->aurfc_delayed_work,
>>> + aurfc_submit_handler);
>>> + spin_lock_init(&hif_dev->aurfc_lock);
>>> + hif_dev->aurfc_active = 1;
>>> +
>>> for (i = 0; i < MAX_RX_URB_NUM; i++) {
>>>
>>> /* Allocate URB */
>>> diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.h b/drivers/net/wireless/ath/ath9k/hif_usb.h
>>> index 51496e7..2050a74 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 AURFC_STEP 10 /* ms */
>>>
>>> #define MAX_REG_OUT_URB_NUM 1
>>> #define MAX_REG_IN_URB_NUM 64
>>> @@ -98,9 +99,17 @@ 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;
>>> struct usb_anchor reg_in_submitted;
>>> struct usb_anchor mgmt_submitted;
>>> struct sk_buff *remain_skb;
>>> +
>>> + /* adaptive usb receive flow control */
>>> + struct delayed_work aurfc_delayed_work;
>>> + spinlock_t aurfc_lock; /* to protect work */
>>> + atomic_t aurfc_submit_delay; /* ms */
>>> + int aurfc_active;
>>> +
>>> 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..1586bd2 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 AURFC_STAT_INC(c) \
>>> + (hif_dev->htc_handle->drv_priv->debug.aurfc_stats.c++)
>>> +#define AURFC_STAT_ADD(c, a) \
>>> + (hif_dev->htc_handle->drv_priv->debug.aurfc_stats.c += a)
>>> +#define AURFC_STAT_SET(c, a) \
>>> + (hif_dev->htc_handle->drv_priv->debug.aurfc_stats.c = a)
>>> +
>>> void ath9k_htc_err_stat_rx(struct ath9k_htc_priv *priv,
>>> struct ath_rx_status *rs);
>>>
>>> @@ -352,11 +359,20 @@ struct ath_skbrx_stats {
>>> u32 skb_dropped;
>>> };
>>>
>>> +struct ath_aurfc_stats {
>>> + u32 aurfc_highwater;
>>> + u32 aurfc_lowwater;
>>> + u32 aurfc_wm_triggered;
>>> + u32 aurfc_submit_delay;
>>> + u32 aurfc_called;
>>> +};
>>> +
>>> 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_aurfc_stats aurfc_stats;
>>> };
>>>
>>> void ath9k_htc_get_et_strings(struct ieee80211_hw *hw,
>>> @@ -377,6 +393,9 @@ void ath9k_htc_get_et_stats(struct ieee80211_hw *hw,
>>>
>>> #define TX_QSTAT_INC(c) do { } while (0)
>>>
>>> +#define AURFC_STAT_INC(c) do {} while (0)
>>> +#define AURFC_STAT_ADD(c, a) do {} while (0)
>>> +#define AURFC_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..a6be9be 100644
>>> --- a/drivers/net/wireless/ath/ath9k/htc_drv_debug.c
>>> +++ b/drivers/net/wireless/ath/ath9k/htc_drv_debug.c
>>> @@ -286,6 +286,54 @@ static const struct file_operations fops_skb_rx = {
>>> .llseek = default_llseek,
>>> };
>>>
>>> +static ssize_t read_file_aurfc(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.aurfc_stats.aurfc_highwater);
>>> + len += scnprintf(buf + len, size - len,
>>> + "%20s : %10u\n", "Low watermark",
>>> + priv->debug.aurfc_stats.aurfc_lowwater);
>>> +
>>> + len += scnprintf(buf + len, size - len,
>>> + "%20s : %10u\n", "WM triggered",
>>> + priv->debug.aurfc_stats.aurfc_wm_triggered);
>>> +
>>> + len += scnprintf(buf + len, size - len,
>>> + "%20s : %10u\n", "Handler called",
>>> + priv->debug.aurfc_stats.aurfc_called);
>>> +
>>> + len += scnprintf(buf + len, size - len,
>>> + "%20s : %10u\n", "Submit delay",
>>> + priv->debug.aurfc_stats.aurfc_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_aurfc = {
>>> + .read = read_file_aurfc,
>>> + .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 +566,12 @@ 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("aurfc_stats", S_IRUSR,
>>> + priv->debug.debugfs_phy,
>>> + priv, &fops_aurfc);
>>> +
>>> 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..939d008 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 usb receive 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;
>>> +
>>> + AURFC_STAT_SET(aurfc_highwater, highwatermark);
>>> + AURFC_STAT_SET(aurfc_lowwater, lowwatermark);
>>> +
>>> do {
>>> + looptimes++;
>>> + if (looptimes > highwatermark) {
>>> + delay = looptimes*AURFC_STEP;
>>> + atomic_set(&hif_dev->aurfc_submit_delay,
>>> + delay);
>>> + AURFC_STAT_INC(aurfc_wm_triggered);
>>> + AURFC_STAT_SET(aurfc_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 +1093,22 @@ void ath9k_rx_tasklet(unsigned long data)
>>>
>>> if (rxbuf == NULL) {
>>> spin_unlock_irqrestore(&priv->rx.rxbuflock, flags);
>>> + spin_lock_irqsave(&hif_dev->aurfc_lock,
>>> + flags);
>>> + if (atomic_read(
>>> + &hif_dev->aurfc_submit_delay) > 0 &&
>>> + hif_dev->aurfc_active > 0)
>>> + mod_delayed_work(system_wq,
>>> + &hif_dev->aurfc_delayed_work,
>>> + 0);
>>> + spin_unlock_irqrestore(&hif_dev->aurfc_lock,
>>> + flags);
>>> + if (looptimes < lowwatermark) {
>>> + atomic_set(&hif_dev->aurfc_submit_delay
>>> + , 0);
>>> + AURFC_STAT_SET(aurfc_submit_delay,
>>> + 0);
>>> + }
>>> break;
>>> }
>>>
>>> @@ -1114,6 +1151,10 @@ void ath9k_htc_rxep(void *drv_priv, struct sk_buff *skb,
>>> struct ath_common *common = ath9k_hw_common(ah);
>>> struct ath9k_htc_rxbuf *rxbuf = NULL, *tmp_buf = NULL;
>>>
>>> + struct htc_target *htc = priv->htc;
>>> + struct hif_device_usb *hif_dev = htc->hif_dev;
>>> + int delay = ATH9K_HTC_RXBUF * AURFC_STEP;
>>> +
>>> spin_lock(&priv->rx.rxbuflock);
>>> list_for_each_entry(tmp_buf, &priv->rx.rxbuf, list) {
>>> if (!tmp_buf->in_process) {
>>> @@ -1124,6 +1165,9 @@ void ath9k_htc_rxep(void *drv_priv, struct sk_buff *skb,
>>> spin_unlock(&priv->rx.rxbuflock);
>>>
>>> if (rxbuf == NULL) {
>>> + atomic_set(&hif_dev->aurfc_submit_delay, delay);
>>> + AURFC_STAT_INC(aurfc_wm_triggered);
>>> + AURFC_STAT_SET(aurfc_submit_delay, delay);
>>> ath_dbg(common, ANY, "No free RX buffer\n");
>>> goto err;
>>> }
>>>
>>
>>
>
>
>
>


--
Regards,
Oleksij

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