From 16f775befc1ccf67e6b223c4d9bb17ac3502ab2c Mon Sep 17 00:00:00 2001 From: Vasily Khoruzhick Date: Fri, 21 Jan 2011 22:44:48 +0200 Subject: libertas_spi: Use workqueue in hw_host_to_card Use workqueue to perform SPI xfers, it's necessary to fix nasty "BUG: scheduling while atomic", because spu_write() calls spi_sync() and spi_sync() may sleep, but hw_host_to_card() callback can be called from atomic context. Remove kthread completely, workqueue now does its job. Restore intermediate buffers which were removed in commit 86c34fe89e9cad9e1ba4d1a8bbf98259035f4caf that introduced mentioned bug. Signed-off-by: Vasily Khoruzhick Signed-off-by: John W. Linville --- drivers/net/wireless/libertas/if_spi.c | 368 +++++++++++++++++++++------------ 1 file changed, 239 insertions(+), 129 deletions(-) (limited to 'drivers/net/wireless/libertas/if_spi.c') diff --git a/drivers/net/wireless/libertas/if_spi.c b/drivers/net/wireless/libertas/if_spi.c index 0060023..f6c2cd6 100644 --- a/drivers/net/wireless/libertas/if_spi.c +++ b/drivers/net/wireless/libertas/if_spi.c @@ -20,10 +20,8 @@ #include #include #include -#include #include #include -#include #include #include #include @@ -34,6 +32,12 @@ #include "dev.h" #include "if_spi.h" +struct if_spi_packet { + struct list_head list; + u16 blen; + u8 buffer[0] __attribute__((aligned(4))); +}; + struct if_spi_card { struct spi_device *spi; struct lbs_private *priv; @@ -51,18 +55,36 @@ struct if_spi_card { unsigned long spu_reg_delay; /* Handles all SPI communication (except for FW load) */ - struct task_struct *spi_thread; - int run_thread; - - /* Used to wake up the spi_thread */ - struct semaphore spi_ready; - struct semaphore spi_thread_terminated; + struct workqueue_struct *workqueue; + struct work_struct packet_work; u8 cmd_buffer[IF_SPI_CMD_BUF_SIZE]; + + /* A buffer of incoming packets from libertas core. + * Since we can't sleep in hw_host_to_card, we have to buffer + * them. */ + struct list_head cmd_packet_list; + struct list_head data_packet_list; + + /* Protects cmd_packet_list and data_packet_list */ + spinlock_t buffer_lock; }; static void free_if_spi_card(struct if_spi_card *card) { + struct list_head *cursor, *next; + struct if_spi_packet *packet; + + list_for_each_safe(cursor, next, &card->cmd_packet_list) { + packet = container_of(cursor, struct if_spi_packet, list); + list_del(&packet->list); + kfree(packet); + } + list_for_each_safe(cursor, next, &card->data_packet_list) { + packet = container_of(cursor, struct if_spi_packet, list); + list_del(&packet->list); + kfree(packet); + } spi_set_drvdata(card->spi, NULL); kfree(card); } @@ -622,7 +644,7 @@ out: /* * SPI Transfer Thread * - * The SPI thread handles all SPI transfers, so there is no need for a lock. + * The SPI worker handles all SPI transfers, so there is no need for a lock. */ /* Move a command from the card to the host */ @@ -742,6 +764,40 @@ out: return err; } +/* Move data or a command from the host to the card. */ +static void if_spi_h2c(struct if_spi_card *card, + struct if_spi_packet *packet, int type) +{ + int err = 0; + u16 int_type, port_reg; + + switch (type) { + case MVMS_DAT: + int_type = IF_SPI_CIC_TX_DOWNLOAD_OVER; + port_reg = IF_SPI_DATA_RDWRPORT_REG; + break; + case MVMS_CMD: + int_type = IF_SPI_CIC_CMD_DOWNLOAD_OVER; + port_reg = IF_SPI_CMD_RDWRPORT_REG; + break; + default: + lbs_pr_err("can't transfer buffer of type %d\n", type); + err = -EINVAL; + goto out; + } + + /* Write the data to the card */ + err = spu_write(card, port_reg, packet->buffer, packet->blen); + if (err) + goto out; + +out: + kfree(packet); + + if (err) + lbs_pr_err("%s: error %d\n", __func__, err); +} + /* Inform the host about a card event */ static void if_spi_e2h(struct if_spi_card *card) { @@ -766,71 +822,88 @@ out: lbs_pr_err("%s: error %d\n", __func__, err); } -static int lbs_spi_thread(void *data) +static void if_spi_host_to_card_worker(struct work_struct *work) { int err; - struct if_spi_card *card = data; + struct if_spi_card *card; u16 hiStatus; + unsigned long flags; + struct if_spi_packet *packet; - while (1) { - /* Wait to be woken up by one of two things. First, our ISR - * could tell us that something happened on the WLAN. - * Secondly, libertas could call hw_host_to_card with more - * data, which we might be able to send. - */ - do { - err = down_interruptible(&card->spi_ready); - if (!card->run_thread) { - up(&card->spi_thread_terminated); - do_exit(0); - } - } while (err == -EINTR); + card = container_of(work, struct if_spi_card, packet_work); - /* Read the host interrupt status register to see what we - * can do. */ - err = spu_read_u16(card, IF_SPI_HOST_INT_STATUS_REG, - &hiStatus); - if (err) { - lbs_pr_err("I/O error\n"); + lbs_deb_enter(LBS_DEB_SPI); + + /* Read the host interrupt status register to see what we + * can do. */ + err = spu_read_u16(card, IF_SPI_HOST_INT_STATUS_REG, + &hiStatus); + if (err) { + lbs_pr_err("I/O error\n"); + goto err; + } + + if (hiStatus & IF_SPI_HIST_CMD_UPLOAD_RDY) { + err = if_spi_c2h_cmd(card); + if (err) goto err; - } + } + if (hiStatus & IF_SPI_HIST_RX_UPLOAD_RDY) { + err = if_spi_c2h_data(card); + if (err) + goto err; + } - if (hiStatus & IF_SPI_HIST_CMD_UPLOAD_RDY) { - err = if_spi_c2h_cmd(card); - if (err) - goto err; - } - if (hiStatus & IF_SPI_HIST_RX_UPLOAD_RDY) { - err = if_spi_c2h_data(card); - if (err) - goto err; + /* workaround: in PS mode, the card does not set the Command + * Download Ready bit, but it sets TX Download Ready. */ + if (hiStatus & IF_SPI_HIST_CMD_DOWNLOAD_RDY || + (card->priv->psstate != PS_STATE_FULL_POWER && + (hiStatus & IF_SPI_HIST_TX_DOWNLOAD_RDY))) { + /* This means two things. First of all, + * if there was a previous command sent, the card has + * successfully received it. + * Secondly, it is now ready to download another + * command. + */ + lbs_host_to_card_done(card->priv); + + /* Do we have any command packets from the host to + * send? */ + packet = NULL; + spin_lock_irqsave(&card->buffer_lock, flags); + if (!list_empty(&card->cmd_packet_list)) { + packet = (struct if_spi_packet *)(card-> + cmd_packet_list.next); + list_del(&packet->list); } + spin_unlock_irqrestore(&card->buffer_lock, flags); - /* workaround: in PS mode, the card does not set the Command - * Download Ready bit, but it sets TX Download Ready. */ - if (hiStatus & IF_SPI_HIST_CMD_DOWNLOAD_RDY || - (card->priv->psstate != PS_STATE_FULL_POWER && - (hiStatus & IF_SPI_HIST_TX_DOWNLOAD_RDY))) { - lbs_host_to_card_done(card->priv); + if (packet) + if_spi_h2c(card, packet, MVMS_CMD); + } + if (hiStatus & IF_SPI_HIST_TX_DOWNLOAD_RDY) { + /* Do we have any data packets from the host to + * send? */ + packet = NULL; + spin_lock_irqsave(&card->buffer_lock, flags); + if (!list_empty(&card->data_packet_list)) { + packet = (struct if_spi_packet *)(card-> + data_packet_list.next); + list_del(&packet->list); } + spin_unlock_irqrestore(&card->buffer_lock, flags); - if (hiStatus & IF_SPI_HIST_CARD_EVENT) - if_spi_e2h(card); + if (packet) + if_spi_h2c(card, packet, MVMS_DAT); + } + if (hiStatus & IF_SPI_HIST_CARD_EVENT) + if_spi_e2h(card); err: - if (err) - lbs_pr_err("%s: got error %d\n", __func__, err); - } -} + if (err) + lbs_pr_err("%s: got error %d\n", __func__, err); -/* Block until lbs_spi_thread thread has terminated */ -static void if_spi_terminate_spi_thread(struct if_spi_card *card) -{ - /* It would be nice to use kthread_stop here, but that function - * can't wake threads waiting for a semaphore. */ - card->run_thread = 0; - up(&card->spi_ready); - down(&card->spi_thread_terminated); + lbs_deb_leave(LBS_DEB_SPI); } /* @@ -842,18 +915,40 @@ static int if_spi_host_to_card(struct lbs_private *priv, u8 type, u8 *buf, u16 nb) { int err = 0; + unsigned long flags; struct if_spi_card *card = priv->card; + struct if_spi_packet *packet; + u16 blen; lbs_deb_enter_args(LBS_DEB_SPI, "type %d, bytes %d", type, nb); - nb = ALIGN(nb, 4); + if (nb == 0) { + lbs_pr_err("%s: invalid size requested: %d\n", __func__, nb); + err = -EINVAL; + goto out; + } + blen = ALIGN(nb, 4); + packet = kzalloc(sizeof(struct if_spi_packet) + blen, GFP_ATOMIC); + if (!packet) { + err = -ENOMEM; + goto out; + } + packet->blen = blen; + memcpy(packet->buffer, buf, nb); + memset(packet->buffer + nb, 0, blen - nb); switch (type) { case MVMS_CMD: - err = spu_write(card, IF_SPI_CMD_RDWRPORT_REG, buf, nb); + priv->dnld_sent = DNLD_CMD_SENT; + spin_lock_irqsave(&card->buffer_lock, flags); + list_add_tail(&packet->list, &card->cmd_packet_list); + spin_unlock_irqrestore(&card->buffer_lock, flags); break; case MVMS_DAT: - err = spu_write(card, IF_SPI_DATA_RDWRPORT_REG, buf, nb); + priv->dnld_sent = DNLD_DATA_SENT; + spin_lock_irqsave(&card->buffer_lock, flags); + list_add_tail(&packet->list, &card->data_packet_list); + spin_unlock_irqrestore(&card->buffer_lock, flags); break; default: lbs_pr_err("can't transfer buffer of type %d", type); @@ -861,6 +956,9 @@ static int if_spi_host_to_card(struct lbs_private *priv, break; } + /* Queue spi xfer work */ + queue_work(card->workqueue, &card->packet_work); +out: lbs_deb_leave_args(LBS_DEB_SPI, "err=%d", err); return err; } @@ -869,13 +967,14 @@ static int if_spi_host_to_card(struct lbs_private *priv, * Host Interrupts * * Service incoming interrupts from the WLAN device. We can't sleep here, so - * don't try to talk on the SPI bus, just wake up the SPI thread. + * don't try to talk on the SPI bus, just queue the SPI xfer work. */ static irqreturn_t if_spi_host_interrupt(int irq, void *dev_id) { struct if_spi_card *card = dev_id; - up(&card->spi_ready); + queue_work(card->workqueue, &card->packet_work); + return IRQ_HANDLED; } @@ -883,56 +982,26 @@ static irqreturn_t if_spi_host_interrupt(int irq, void *dev_id) * SPI callbacks */ -static int __devinit if_spi_probe(struct spi_device *spi) +static int if_spi_init_card(struct if_spi_card *card) { - struct if_spi_card *card; - struct lbs_private *priv = NULL; - struct libertas_spi_platform_data *pdata = spi->dev.platform_data; - int err = 0, i; + struct spi_device *spi = card->spi; + int err, i; u32 scratch; - struct sched_param param = { .sched_priority = 1 }; const struct firmware *helper = NULL; const struct firmware *mainfw = NULL; lbs_deb_enter(LBS_DEB_SPI); - if (!pdata) { - err = -EINVAL; - goto out; - } - - if (pdata->setup) { - err = pdata->setup(spi); - if (err) - goto out; - } - - /* Allocate card structure to represent this specific device */ - card = kzalloc(sizeof(struct if_spi_card), GFP_KERNEL); - if (!card) { - err = -ENOMEM; - goto out; - } - spi_set_drvdata(spi, card); - card->pdata = pdata; - card->spi = spi; - card->prev_xfer_time = jiffies; - - sema_init(&card->spi_ready, 0); - sema_init(&card->spi_thread_terminated, 0); - - /* Initialize the SPI Interface Unit */ - err = spu_init(card, pdata->use_dummy_writes); + err = spu_init(card, card->pdata->use_dummy_writes); if (err) - goto free_card; + goto out; err = spu_get_chip_revision(card, &card->card_id, &card->card_rev); if (err) - goto free_card; + goto out; - /* Firmware load */ err = spu_read_u32(card, IF_SPI_SCRATCH_4_REG, &scratch); if (err) - goto free_card; + goto out; if (scratch == SUCCESSFUL_FW_DOWNLOAD_MAGIC) lbs_deb_spi("Firmware is already loaded for " "Marvell WLAN 802.11 adapter\n"); @@ -946,7 +1015,7 @@ static int __devinit if_spi_probe(struct spi_device *spi) lbs_pr_err("Unsupported chip_id: 0x%02x\n", card->card_id); err = -ENODEV; - goto free_card; + goto out; } err = lbs_get_firmware(&card->spi->dev, NULL, NULL, @@ -954,7 +1023,7 @@ static int __devinit if_spi_probe(struct spi_device *spi) &mainfw); if (err) { lbs_pr_err("failed to find firmware (%d)\n", err); - goto free_card; + goto out; } lbs_deb_spi("Initializing FW for Marvell WLAN 802.11 adapter " @@ -966,15 +1035,68 @@ static int __devinit if_spi_probe(struct spi_device *spi) spi->max_speed_hz); err = if_spi_prog_helper_firmware(card, helper); if (err) - goto free_card; + goto out; err = if_spi_prog_main_firmware(card, mainfw); if (err) - goto free_card; + goto out; lbs_deb_spi("loaded FW for Marvell WLAN 802.11 adapter\n"); } err = spu_set_interrupt_mode(card, 0, 1); if (err) + goto out; + +out: + if (helper) + release_firmware(helper); + if (mainfw) + release_firmware(mainfw); + + lbs_deb_leave_args(LBS_DEB_SPI, "err %d\n", err); + + return err; +} + +static int __devinit if_spi_probe(struct spi_device *spi) +{ + struct if_spi_card *card; + struct lbs_private *priv = NULL; + struct libertas_spi_platform_data *pdata = spi->dev.platform_data; + int err = 0; + + lbs_deb_enter(LBS_DEB_SPI); + + if (!pdata) { + err = -EINVAL; + goto out; + } + + if (pdata->setup) { + err = pdata->setup(spi); + if (err) + goto out; + } + + /* Allocate card structure to represent this specific device */ + card = kzalloc(sizeof(struct if_spi_card), GFP_KERNEL); + if (!card) { + err = -ENOMEM; + goto teardown; + } + spi_set_drvdata(spi, card); + card->pdata = pdata; + card->spi = spi; + card->prev_xfer_time = jiffies; + + INIT_LIST_HEAD(&card->cmd_packet_list); + INIT_LIST_HEAD(&card->data_packet_list); + spin_lock_init(&card->buffer_lock); + + /* Initialize the SPI Interface Unit */ + + /* Firmware load */ + err = if_spi_init_card(card); + if (err) goto free_card; /* Register our card with libertas. @@ -993,27 +1115,16 @@ static int __devinit if_spi_probe(struct spi_device *spi) priv->fw_ready = 1; /* Initialize interrupt handling stuff. */ - card->run_thread = 1; - card->spi_thread = kthread_run(lbs_spi_thread, card, "lbs_spi_thread"); - if (IS_ERR(card->spi_thread)) { - card->run_thread = 0; - err = PTR_ERR(card->spi_thread); - lbs_pr_err("error creating SPI thread: err=%d\n", err); - goto remove_card; - } - if (sched_setscheduler(card->spi_thread, SCHED_FIFO, ¶m)) - lbs_pr_err("Error setting scheduler, using default.\n"); + card->workqueue = create_workqueue("libertas_spi"); + INIT_WORK(&card->packet_work, if_spi_host_to_card_worker); err = request_irq(spi->irq, if_spi_host_interrupt, IRQF_TRIGGER_FALLING, "libertas_spi", card); if (err) { lbs_pr_err("can't get host irq line-- request_irq failed\n"); - goto terminate_thread; + goto terminate_workqueue; } - /* poke the IRQ handler so that we don't miss the first interrupt */ - up(&card->spi_ready); - /* Start the card. * This will call register_netdev, and we'll start * getting interrupts... */ @@ -1028,18 +1139,16 @@ static int __devinit if_spi_probe(struct spi_device *spi) release_irq: free_irq(spi->irq, card); -terminate_thread: - if_spi_terminate_spi_thread(card); -remove_card: +terminate_workqueue: + flush_workqueue(card->workqueue); + destroy_workqueue(card->workqueue); lbs_remove_card(priv); /* will call free_netdev */ free_card: free_if_spi_card(card); +teardown: + if (pdata->teardown) + pdata->teardown(spi); out: - if (helper) - release_firmware(helper); - if (mainfw) - release_firmware(mainfw); - lbs_deb_leave_args(LBS_DEB_SPI, "err %d\n", err); return err; } @@ -1056,7 +1165,8 @@ static int __devexit libertas_spi_remove(struct spi_device *spi) lbs_remove_card(priv); /* will call free_netdev */ free_irq(spi->irq, card); - if_spi_terminate_spi_thread(card); + flush_workqueue(card->workqueue); + destroy_workqueue(card->workqueue); if (card->pdata->teardown) card->pdata->teardown(spi); free_if_spi_card(card); -- cgit v1.1