From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760730AbbA3K4O (ORCPT ); Fri, 30 Jan 2015 05:56:14 -0500 Received: from mout.gmx.net ([212.227.15.15]:61788 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752685AbbA3K4G (ORCPT ); Fri, 30 Jan 2015 05:56:06 -0500 Message-ID: <54CB6326.2070803@rempel-privat.de> Date: Fri, 30 Jan 2015 11:55:34 +0100 From: Oleksij Rempel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: yuweizheng@139.com, linux-kernel@vger.kernel.org, ath9k-devel@venema.h4ckr.net, linux-wireless@vger.kernel.org, kvalo@codeaurora.org, ath9k-devel@qca.qualcomm.com CC: netdev@vger.kernel.org, Yuwei Zheng Subject: Re: [PATCH] Repair soft lockup with monitor mode of ath9k_htc card References: <1422486872-16308-1-git-send-email-yuweizheng@139.com> In-Reply-To: <1422486872-16308-1-git-send-email-yuweizheng@139.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="j2DGpl7q5fg70tApro8kAv1sp8Fk1ep3f" X-Provags-ID: V03:K0:zPZ3cQPCEkRbtQDj2AgZne8Yej4nyDj7idVWmAASu1bP7fKeEI6 sB4A/jZ5VYr7m2ZJeu1WP7mW27203ujfurEAgl3x1J1SgC5tV7vhGow/Qi8puYFaXcjYzp8 53vjDMv5eCKGXTyw/bpSOU9M8j7K0gtBjiJayK3p3RO4/uwBRWf5G0hI8McoVU/hRBfWIEv JztEKqk5sPFiKcKCgM1Eg== X-UI-Out-Filterresults: notjunk:1; Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --j2DGpl7q5fg70tApro8kAv1sp8Fk1ep3f Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Am 29.01.2015 um 00:14 schrieb yuweizheng@139.com: > From: Yuwei Zheng >=20 > In the environment with heavy wifi traffic, set the ar9271 into monitor= mode, will > trigger a deadloop panic. > =20 > 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 m= ore chance to excute than > ath9k_rx_tasklet. So in the worst condition, the rx.rxbuf receive lis= t is always full, > and the do {}while(true) loop will not be break. The kernel get a soft = lockup panic.=20 Please note, ath9k_htc is also used on HW where real hrtimer actually exist. It should behave differently and produce different load on the system. The overhead of setting up the hrtimers *may* not be worth it. Depending on the load, it may provide lots of avoidable interrupts. Did you tried to use simple tasklet_start? > [59011.007210] BUG: soft lockup - CPU#0 stuck for 23s! > [kworker/0:0:30609] > [59011.030560] BUG: scheduling while atomic: kworker/0:0/30609/0x400101= 00 > [59013.804486] BUG: scheduling while atomic: kworker/0:0/30609/0x400101= 00 > [59013.858522] Kernel panic - not syncing: softlockup: hung tasks > =20 > [59014.038891] Exception stack(0xdf4bbc38 to 0xdf4bbc80) > [59014.046834] bc20: = de57b950 60000113 > [59014.059579] bc40: 00000000 bb32bb32 60000113 de57b948 de57b500 dc7bb= 440 df4bbcd0 00000000 > [59014.072337] bc60: de57b950 60000113 df4bbcd0 df4bbc80 c04c259d c04c2= 5a0 60000133 ffffffff > [59014.085233] [] (__irq_svc+0x3b/0x5c) from [] (_r= aw_spin_unlock_irqrestore+0xc/0x10) > [59014.100437] [] (_raw_spin_unlock_irqrestore+0xc/0x10) from= [] (ath9k_rx_tasklet+0x290/0x490 [ath9k_htc]) > [59014.118267] [] (ath9k_rx_tasklet+0x290/0x490 [ath9k_htc]) = from [] (tasklet_action+0x3b/0x98) > [59014.134132] [] (tasklet_action+0x3b/0x98) from [= ] (__do_softirq+0x99/0x16c) > [59014.147784] [] (__do_softirq+0x99/0x16c) from []= (irq_exit+0x5b/0x5c) > [59014.160653] [] (irq_exit+0x5b/0x5c) from [] (han= dle_IRQ+0x37/0x78) > [59014.173124] [] (handle_IRQ+0x37/0x78) from [] (o= map3_intc_handle_irq+0x5f/0x68) > [59014.187225] [] (omap3_intc_handle_irq+0x5f/0x68) from [](__irq_svc+0x3b/0x5c) > =20 > This bug can be see with low performance board, such as uniprocessor be= agle bone board. > =20 > =20 > Signed-off-by: Yuwei Zheng > Signed-off-by: Yuwei Zheng >=20 >=20 > --- > drivers/net/wireless/ath/ath9k/hif_usb.c | 58 ++++++++++++++++++= ++++---- > 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, 144 insertions(+), 7 deletions(-) >=20 > diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wir= eless/ath/ath9k/hif_usb.c > index 8e7153b..18c6f0e 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 !=3D 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 =3D 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 =3D 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 =3D usb_submit_urb(urb, GFP_ATOMIC); > + if (ret) { > + usb_unanchor_urb(urb); > + goto free; > + } > } > =20 > return; > @@ -818,9 +823,39 @@ err: > return -ENOMEM; > } > =20 > +static enum hrtimer_restart rx_urb_submit_timer_handler(struct hrtimer= *me) > +{ > + struct tasklet_hrtimer *thr =3D > + container_of(me, struct tasklet_hrtimer, timer); > + struct hif_device_usb *hif_dev =3D > + container_of(thr, struct hif_device_usb, rx_submit_timer); > + struct urb *urb =3D NULL; > + struct sk_buff *skb =3D NULL; > + int ret; > + > + while (true) { > + urb =3D usb_get_from_anchor(&hif_dev->rx_delayed_submitted); > + if (urb !=3D NULL) { > + skb =3D (struct sk_buff *)urb->context; > + ret =3D usb_submit_urb(urb, GFP_ATOMIC); > + if (ret !=3D -EBUSY) { > + usb_unanchor_urb(urb); > + dev_kfree_skb_any(skb); > + urb->context =3D NULL; > + } > + } else { > + break; > + } > + } > + > + return HRTIMER_NORESTART; > +} > + > static void ath9k_hif_usb_dealloc_rx_urbs(struct hif_device_usb *hif_d= ev) > { > 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); > } > =20 > static int ath9k_hif_usb_alloc_rx_urbs(struct hif_device_usb *hif_dev)= > @@ -830,6 +865,8 @@ static int ath9k_hif_usb_alloc_rx_urbs(struct hif_d= evice_usb *hif_dev) > int i, ret; > =20 > init_usb_anchor(&hif_dev->rx_submitted); > + init_usb_anchor(&hif_dev->rx_delayed_submitted); > + > spin_lock_init(&hif_dev->rx_lock); > =20 > for (i =3D 0; i < MAX_RX_URB_NUM; i++) { > @@ -871,6 +908,13 @@ static int ath9k_hif_usb_alloc_rx_urbs(struct hif_= device_usb *hif_dev) > usb_free_urb(urb); > } > =20 > + /* 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; > =20 > err_submit: > diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.h b/drivers/net/wir= eless/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/wireles= s/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) > =20 > #define TX_QSTAT_INC(q) (priv->debug.tx_stats.queue_stats[q]++) > =20 > +#define TASKLETRX_STAT_INC(c) (hif_dev->htc_handle->drv_priv->debug.ta= skletrx_stats.c++) > +#define TASKLETRX_STAT_ADD(c, a) (hif_dev->htc_handle->drv_priv->debug= =2Etaskletrx_stats.c +=3D a) > +#define TASKLETRX_STAT_SET(c, a) (hif_dev->htc_handle->drv_priv->debug= =2Etaskletrx_stats.c =3D a) > + > void ath9k_htc_err_stat_rx(struct ath9k_htc_priv *priv, > struct ath_rx_status *rs); > =20 > @@ -352,11 +356,20 @@ struct ath_skbrx_stats { > u32 skb_dropped; > }; > =20 > +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; > }; > =20 > void ath9k_htc_get_et_strings(struct ieee80211_hw *hw, > diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_debug.c b/drivers/n= et/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 =3D= { > .llseek =3D default_llseek, > }; > =20 > +static ssize_t read_file_tasklet_rx(struct file *file, char __user *us= er_buf, > + size_t count, loff_t *ppos) > +{ > + struct ath9k_htc_priv *priv =3D file->private_data; > + char *buf; > + unsigned int len =3D 0, size =3D 1500; > + ssize_t retval =3D 0; > + > + buf =3D kzalloc(size, GFP_KERNEL); > + if (buf =3D=3D NULL) > + return -ENOMEM; > + > + len +=3D scnprintf(buf + len, size - len, > + "%20s : %10u\n", "Loop times", > + priv->debug.taskletrx_stats.taskletrx_looptimes); > + len +=3D scnprintf(buf + len, size - len, > + "%20s : %10u\n", "High watermark", > + priv->debug.taskletrx_stats.taskletrx_highwater); > + len +=3D scnprintf(buf + len, size - len, > + "%20s : %10u\n", "Low watermark", > + priv->debug.taskletrx_stats.taskletrx_lowwater); > + > + len +=3D scnprintf(buf + len, size - len, > + "%20s : %10u\n", "WM triggered", > + priv->debug.taskletrx_stats.taskletrx_watermark_triggered); > + > + len +=3D scnprintf(buf + len, size - len, > + "%20s : %10u\n", "URB delay", > + priv->debug.taskletrx_stats.taskletrx_urb_submit_delay); > + if (len > size) > + len =3D size; > + > + retval =3D simple_read_from_buffer(user_buf, count, ppos, buf, len); > + kfree(buf); > + > + return retval; > +} > + > +static const struct file_operations fops_tasklet_rx =3D { > + .read =3D read_file_tasklet_rx, > + .open =3D simple_open, > + .owner =3D THIS_MODULE, > + .llseek =3D 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); > =20 > + 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_stat= s); > =20 > debugfs_create_file("slot", S_IRUSR, priv->debug.debugfs_phy, > diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c b/drivers/ne= t/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; > =20 > + /* add for adaptive flow control*/ > + int looptimes =3D 0; > + int highwatermark =3D ATH9K_HTC_RXBUF*3/4; > + int lowwatermark =3D ATH9K_HTC_RXBUF/4; > + unsigned int delay =3D 0; > + > + struct htc_target *htc =3D priv->htc; > + struct hif_device_usb *hif_dev =3D 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 =3D 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) > =20 > if (rxbuf =3D=3D 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; > } > =20 >=20 --=20 Regards, Oleksij --j2DGpl7q5fg70tApro8kAv1sp8Fk1ep3f Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iF4EAREIAAYFAlTLYyYACgkQHwImuRkmbWnWGQEAiObt/z0JDYkpquV+x/ICyzoe dtlzbDYnpW3jj+bDQNUA/RmiCzBQhxZIpbOJY813loUSJaf8ChK91juRjJw0/Km8 =0uiG -----END PGP SIGNATURE----- --j2DGpl7q5fg70tApro8kAv1sp8Fk1ep3f--