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Revert "tty: n_gsm: avoid call of sleeping functions from atomic context"
This reverts commit902e02ea93
. The above commit is reverted as the usage of tx_mutex seems not to solve the problem described in902e02ea93
("tty: n_gsm: avoid call of sleeping functions from atomic context") and just moves the bug to another place. Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru> Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Reviewed-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20221008110221.13645-2-pchelkin@ispras.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
4561d8008a
commit
acdab4cb4b
1 changed files with 29 additions and 24 deletions
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@ -264,7 +264,7 @@ struct gsm_mux {
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bool constipated; /* Asked by remote to shut up */
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bool has_devices; /* Devices were registered */
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struct mutex tx_mutex;
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spinlock_t tx_lock;
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unsigned int tx_bytes; /* TX data outstanding */
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#define TX_THRESH_HI 8192
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#define TX_THRESH_LO 2048
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@ -700,6 +700,7 @@ static int gsm_send(struct gsm_mux *gsm, int addr, int cr, int control)
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struct gsm_msg *msg;
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u8 *dp;
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int ocr;
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unsigned long flags;
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msg = gsm_data_alloc(gsm, addr, 0, control);
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if (!msg)
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@ -721,10 +722,10 @@ static int gsm_send(struct gsm_mux *gsm, int addr, int cr, int control)
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gsm_print_packet("Q->", addr, cr, control, NULL, 0);
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mutex_lock(&gsm->tx_mutex);
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spin_lock_irqsave(&gsm->tx_lock, flags);
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list_add_tail(&msg->list, &gsm->tx_ctrl_list);
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gsm->tx_bytes += msg->len;
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mutex_unlock(&gsm->tx_mutex);
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spin_unlock_irqrestore(&gsm->tx_lock, flags);
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gsmld_write_trigger(gsm);
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return 0;
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@ -749,7 +750,7 @@ static void gsm_dlci_clear_queues(struct gsm_mux *gsm, struct gsm_dlci *dlci)
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spin_unlock_irqrestore(&dlci->lock, flags);
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/* Clear data packets in MUX write queue */
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mutex_lock(&gsm->tx_mutex);
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spin_lock_irqsave(&gsm->tx_lock, flags);
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list_for_each_entry_safe(msg, nmsg, &gsm->tx_data_list, list) {
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if (msg->addr != addr)
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continue;
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@ -757,7 +758,7 @@ static void gsm_dlci_clear_queues(struct gsm_mux *gsm, struct gsm_dlci *dlci)
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list_del(&msg->list);
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kfree(msg);
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}
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mutex_unlock(&gsm->tx_mutex);
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spin_unlock_irqrestore(&gsm->tx_lock, flags);
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}
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/**
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@ -1043,9 +1044,10 @@ static void __gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg)
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static void gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg)
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{
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mutex_lock(&dlci->gsm->tx_mutex);
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unsigned long flags;
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spin_lock_irqsave(&dlci->gsm->tx_lock, flags);
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__gsm_data_queue(dlci, msg);
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mutex_unlock(&dlci->gsm->tx_mutex);
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spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags);
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}
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/**
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@ -1057,7 +1059,7 @@ static void gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg)
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* is data. Keep to the MRU of the mux. This path handles the usual tty
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* interface which is a byte stream with optional modem data.
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*
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* Caller must hold the tx_mutex of the mux.
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* Caller must hold the tx_lock of the mux.
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*/
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static int gsm_dlci_data_output(struct gsm_mux *gsm, struct gsm_dlci *dlci)
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@ -1117,7 +1119,7 @@ static int gsm_dlci_data_output(struct gsm_mux *gsm, struct gsm_dlci *dlci)
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* is data. Keep to the MRU of the mux. This path handles framed data
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* queued as skbuffs to the DLCI.
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*
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* Caller must hold the tx_mutex of the mux.
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* Caller must hold the tx_lock of the mux.
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*/
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static int gsm_dlci_data_output_framed(struct gsm_mux *gsm,
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@ -1133,7 +1135,7 @@ static int gsm_dlci_data_output_framed(struct gsm_mux *gsm,
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if (dlci->adaption == 4)
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overhead = 1;
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/* dlci->skb is locked by tx_mutex */
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/* dlci->skb is locked by tx_lock */
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if (dlci->skb == NULL) {
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dlci->skb = skb_dequeue_tail(&dlci->skb_list);
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if (dlci->skb == NULL)
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@ -1187,7 +1189,7 @@ static int gsm_dlci_data_output_framed(struct gsm_mux *gsm,
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* Push an empty frame in to the transmit queue to update the modem status
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* bits and to transmit an optional break.
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*
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* Caller must hold the tx_mutex of the mux.
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* Caller must hold the tx_lock of the mux.
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*/
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static int gsm_dlci_modem_output(struct gsm_mux *gsm, struct gsm_dlci *dlci,
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@ -1301,12 +1303,13 @@ static int gsm_dlci_data_sweep(struct gsm_mux *gsm)
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static void gsm_dlci_data_kick(struct gsm_dlci *dlci)
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{
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unsigned long flags;
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int sweep;
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if (dlci->constipated)
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return;
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mutex_lock(&dlci->gsm->tx_mutex);
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spin_lock_irqsave(&dlci->gsm->tx_lock, flags);
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/* If we have nothing running then we need to fire up */
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sweep = (dlci->gsm->tx_bytes < TX_THRESH_LO);
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if (dlci->gsm->tx_bytes == 0) {
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@ -1317,7 +1320,7 @@ static void gsm_dlci_data_kick(struct gsm_dlci *dlci)
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}
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if (sweep)
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gsm_dlci_data_sweep(dlci->gsm);
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mutex_unlock(&dlci->gsm->tx_mutex);
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spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags);
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}
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/*
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@ -2029,13 +2032,14 @@ static void gsm_dlci_command(struct gsm_dlci *dlci, const u8 *data, int len)
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static void gsm_kick_timeout(struct work_struct *work)
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{
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struct gsm_mux *gsm = container_of(work, struct gsm_mux, kick_timeout.work);
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unsigned long flags;
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int sent = 0;
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mutex_lock(&gsm->tx_mutex);
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spin_lock_irqsave(&gsm->tx_lock, flags);
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/* If we have nothing running then we need to fire up */
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if (gsm->tx_bytes < TX_THRESH_LO)
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sent = gsm_dlci_data_sweep(gsm);
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mutex_unlock(&gsm->tx_mutex);
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spin_unlock_irqrestore(&gsm->tx_lock, flags);
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if (sent && debug & DBG_DATA)
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pr_info("%s TX queue stalled\n", __func__);
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@ -2565,7 +2569,6 @@ static void gsm_free_mux(struct gsm_mux *gsm)
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break;
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}
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}
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mutex_destroy(&gsm->tx_mutex);
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mutex_destroy(&gsm->mutex);
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kfree(gsm->txframe);
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kfree(gsm->buf);
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@ -2637,7 +2640,6 @@ static struct gsm_mux *gsm_alloc_mux(void)
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}
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spin_lock_init(&gsm->lock);
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mutex_init(&gsm->mutex);
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mutex_init(&gsm->tx_mutex);
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kref_init(&gsm->ref);
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INIT_LIST_HEAD(&gsm->tx_ctrl_list);
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INIT_LIST_HEAD(&gsm->tx_data_list);
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@ -2646,6 +2648,7 @@ static struct gsm_mux *gsm_alloc_mux(void)
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INIT_WORK(&gsm->tx_work, gsmld_write_task);
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init_waitqueue_head(&gsm->event);
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spin_lock_init(&gsm->control_lock);
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spin_lock_init(&gsm->tx_lock);
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gsm->t1 = T1;
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gsm->t2 = T2;
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@ -2670,7 +2673,6 @@ static struct gsm_mux *gsm_alloc_mux(void)
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}
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spin_unlock(&gsm_mux_lock);
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if (i == MAX_MUX) {
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mutex_destroy(&gsm->tx_mutex);
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mutex_destroy(&gsm->mutex);
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kfree(gsm->txframe);
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kfree(gsm->buf);
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@ -2826,16 +2828,17 @@ static void gsmld_write_trigger(struct gsm_mux *gsm)
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static void gsmld_write_task(struct work_struct *work)
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{
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struct gsm_mux *gsm = container_of(work, struct gsm_mux, tx_work);
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unsigned long flags;
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int i, ret;
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/* All outstanding control channel and control messages and one data
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* frame is sent.
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*/
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ret = -ENODEV;
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mutex_lock(&gsm->tx_mutex);
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spin_lock_irqsave(&gsm->tx_lock, flags);
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if (gsm->tty)
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ret = gsm_data_kick(gsm);
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mutex_unlock(&gsm->tx_mutex);
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spin_unlock_irqrestore(&gsm->tx_lock, flags);
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if (ret >= 0)
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for (i = 0; i < NUM_DLCI; i++)
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@ -3042,6 +3045,7 @@ static ssize_t gsmld_write(struct tty_struct *tty, struct file *file,
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const unsigned char *buf, size_t nr)
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{
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struct gsm_mux *gsm = tty->disc_data;
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unsigned long flags;
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int space;
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int ret;
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@ -3049,13 +3053,13 @@ static ssize_t gsmld_write(struct tty_struct *tty, struct file *file,
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return -ENODEV;
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ret = -ENOBUFS;
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mutex_lock(&gsm->tx_mutex);
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spin_lock_irqsave(&gsm->tx_lock, flags);
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space = tty_write_room(tty);
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if (space >= nr)
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ret = tty->ops->write(tty, buf, nr);
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else
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set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
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mutex_unlock(&gsm->tx_mutex);
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spin_unlock_irqrestore(&gsm->tx_lock, flags);
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return ret;
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}
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@ -3352,13 +3356,14 @@ static struct tty_ldisc_ops tty_ldisc_packet = {
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static void gsm_modem_upd_via_data(struct gsm_dlci *dlci, u8 brk)
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{
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struct gsm_mux *gsm = dlci->gsm;
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unsigned long flags;
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if (dlci->state != DLCI_OPEN || dlci->adaption != 2)
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return;
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mutex_lock(&gsm->tx_mutex);
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spin_lock_irqsave(&gsm->tx_lock, flags);
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gsm_dlci_modem_output(gsm, dlci, brk);
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mutex_unlock(&gsm->tx_mutex);
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spin_unlock_irqrestore(&gsm->tx_lock, flags);
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}
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/**
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