On 25/08/2021 10:41, Deborah Brouwer wrote:
> Currently, the vivid emulation of cec message transmission does not force
> adapters to wait until the cec bus has been signal-free for a certain
> number of bit periods before transmitting or re-transmitting a message.
> Without enforcing the signal-free time requirements, adapters do not share
> the bus very well and some messages are sent too quickly while other
> messages are lost. By emulating a signal-free time and forcing adapters
> to wait their turn to transmit, the vivid emulation of cec transmission
> is much more reliable.
>
> Signed-off-by: Deborah Brouwer <deborahbrouwer3563@xxxxxxxxx>
> ---
> Changes since v1:
> - use actual message length instead of max when copying
> - check for kthread_stop() within bus
> - store the last_initiator in the vivid state
> - update the last_initiator as soon as it is known and adjust sfts
> - use last_initiator to assign sft when transmit is called
> - use function for division
>
> drivers/media/test-drivers/vivid/vivid-cec.c | 341 ++++++++++--------
> drivers/media/test-drivers/vivid/vivid-cec.h | 9 +-
> drivers/media/test-drivers/vivid/vivid-core.c | 37 +-
> drivers/media/test-drivers/vivid/vivid-core.h | 23 +-
> 4 files changed, 218 insertions(+), 192 deletions(-)
>
> diff --git a/drivers/media/test-drivers/vivid/vivid-cec.c b/drivers/media/test-drivers/vivid/vivid-cec.c
> index 4d2413e87730..d97da4f10ad7 100644
> --- a/drivers/media/test-drivers/vivid/vivid-cec.c
> +++ b/drivers/media/test-drivers/vivid/vivid-cec.c
> @@ -5,40 +5,23 @@
> * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
> */
>
> +#include <linux/delay.h>
> #include <media/cec.h>
>
> #include "vivid-core.h"
> #include "vivid-cec.h"
>
> -#define CEC_TIM_START_BIT_TOTAL 4500
> -#define CEC_TIM_START_BIT_LOW 3700
> -#define CEC_TIM_START_BIT_HIGH 800
> -#define CEC_TIM_DATA_BIT_TOTAL 2400
> -#define CEC_TIM_DATA_BIT_0_LOW 1500
> -#define CEC_TIM_DATA_BIT_0_HIGH 900
> -#define CEC_TIM_DATA_BIT_1_LOW 600
> -#define CEC_TIM_DATA_BIT_1_HIGH 1800
> +#define CEC_START_BIT_US 4500
> +#define CEC_DATA_BIT_US 2400
> +#define CEC_MARGIN_US 350
>
> -void vivid_cec_bus_free_work(struct vivid_dev *dev)
> -{
> - spin_lock(&dev->cec_slock);
> - while (!list_empty(&dev->cec_work_list)) {
> - struct vivid_cec_work *cw =
> - list_first_entry(&dev->cec_work_list,
> - struct vivid_cec_work, list);
> -
> - spin_unlock(&dev->cec_slock);
> - cancel_delayed_work_sync(&cw->work);
> - spin_lock(&dev->cec_slock);
> - list_del(&cw->list);
> - cec_transmit_attempt_done(cw->adap, CEC_TX_STATUS_LOW_DRIVE);
> - kfree(cw);
> - }
> - spin_unlock(&dev->cec_slock);
> -}
> +struct xfer_on_bus {
> + struct cec_adapter *adap;
> + u8 status;
> +};
>
> -static bool vivid_cec_find_dest_adap(struct vivid_dev *dev,
> - struct cec_adapter *adap, u8 dest)
> +static bool find_dest_adap(struct vivid_dev *dev,
> + struct cec_adapter *adap, u8 dest)
> {
> unsigned int i;
>
> @@ -61,116 +44,187 @@ static bool vivid_cec_find_dest_adap(struct vivid_dev *dev,
> return false;
> }
>
> -static void vivid_cec_pin_adap_events(struct cec_adapter *adap, ktime_t ts,
> - const struct cec_msg *msg, bool nacked)
> +static bool xfer_ready(struct vivid_dev *dev)
> {
> - unsigned int len = nacked ? 1 : msg->len;
> unsigned int i;
> - bool bit;
> -
> - if (adap == NULL)
> - return;
> + bool ready = false;
>
> - /*
> - * Suffix ULL on constant 10 makes the expression
> - * CEC_TIM_START_BIT_TOTAL + 10ULL * len * CEC_TIM_DATA_BIT_TOTAL
> - * to be evaluated using 64-bit unsigned arithmetic (u64), which
> - * is what ktime_sub_us expects as second argument.
> - */
> - ts = ktime_sub_us(ts, CEC_TIM_START_BIT_TOTAL +
> - 10ULL * len * CEC_TIM_DATA_BIT_TOTAL);
> - cec_queue_pin_cec_event(adap, false, false, ts);
> - ts = ktime_add_us(ts, CEC_TIM_START_BIT_LOW);
> - cec_queue_pin_cec_event(adap, true, false, ts);
> - ts = ktime_add_us(ts, CEC_TIM_START_BIT_HIGH);
> -
> - for (i = 0; i < 10 * len; i++) {
> - switch (i % 10) {
> - case 0 ... 7:
> - bit = msg->msg[i / 10] & (0x80 >> (i % 10));
> - break;
> - case 8: /* EOM */
> - bit = i / 10 == msg->len - 1;
> - break;
> - case 9: /* ACK */
> - bit = cec_msg_is_broadcast(msg) ^ nacked;
> + spin_lock(&dev->cec_xfers_slock);
> + for (i = 0; i < ARRAY_SIZE(dev->xfers); i++) {
> + if (dev->xfers[i].sft &&
> + dev->xfers[i].sft <= dev->cec_sft) {
> + ready = true;
> break;
> }
> - cec_queue_pin_cec_event(adap, false, false, ts);
> - if (bit)
> - ts = ktime_add_us(ts, CEC_TIM_DATA_BIT_1_LOW);
> - else
> - ts = ktime_add_us(ts, CEC_TIM_DATA_BIT_0_LOW);
> - cec_queue_pin_cec_event(adap, true, false, ts);
> - if (bit)
> - ts = ktime_add_us(ts, CEC_TIM_DATA_BIT_1_HIGH);
> - else
> - ts = ktime_add_us(ts, CEC_TIM_DATA_BIT_0_HIGH);
> }
> -}
> + spin_unlock(&dev->cec_xfers_slock);
>
> -static void vivid_cec_pin_events(struct vivid_dev *dev,
> - const struct cec_msg *msg, bool nacked)
> -{
> - ktime_t ts = ktime_get();
> - unsigned int i;
> -
> - vivid_cec_pin_adap_events(dev->cec_rx_adap, ts, msg, nacked);
> - for (i = 0; i < MAX_OUTPUTS; i++)
> - vivid_cec_pin_adap_events(dev->cec_tx_adap[i], ts, msg, nacked);
> + return ready;
> }
>
> -static void vivid_cec_xfer_done_worker(struct work_struct *work)
> +/*
> + * If an adapter tries to send successive messages, it must wait for the
> + * longest signal-free time between its transmissions. But, if another
> + * adapter sends a message in the interim, then the wait can be reduced
> + * because the messages are no longer successive. Make these adjustments
> + * if necessary. Should be called holding cec_xfers_slock.
> + */
> +static void adjust_sfts(struct vivid_dev *dev)
> {
> - struct vivid_cec_work *cw =
> - container_of(work, struct vivid_cec_work, work.work);
> - struct vivid_dev *dev = cw->dev;
> - struct cec_adapter *adap = cw->adap;
> - u8 dest = cec_msg_destination(&cw->msg);
> - bool valid_dest;
> unsigned int i;
> + u8 initiator;
>
> - valid_dest = cec_msg_is_broadcast(&cw->msg);
> - if (!valid_dest)
> - valid_dest = vivid_cec_find_dest_adap(dev, adap, dest);
> -
> - cw->tx_status = valid_dest ? CEC_TX_STATUS_OK : CEC_TX_STATUS_NACK;
> - spin_lock(&dev->cec_slock);
> - dev->cec_xfer_time_jiffies = 0;
> - dev->cec_xfer_start_jiffies = 0;
> - list_del(&cw->list);
> - spin_unlock(&dev->cec_slock);
> - vivid_cec_pin_events(dev, &cw->msg, !valid_dest);
> - cec_transmit_attempt_done(cw->adap, cw->tx_status);
> -
> - /* Broadcast message */
> - if (adap != dev->cec_rx_adap)
> - cec_received_msg(dev->cec_rx_adap, &cw->msg);
> - for (i = 0; i < MAX_OUTPUTS && dev->cec_tx_adap[i]; i++)
> - if (adap != dev->cec_tx_adap[i])
> - cec_received_msg(dev->cec_tx_adap[i], &cw->msg);
> - kfree(cw);
> + for (i = 0; i < ARRAY_SIZE(dev->xfers); i++) {
> + if (dev->xfers[i].sft <= CEC_SIGNAL_FREE_TIME_RETRY)
> + continue;
> + initiator = dev->xfers[i].msg[0] >> 4;
> + if (initiator == dev->last_initiator)
> + dev->xfers[i].sft = CEC_SIGNAL_FREE_TIME_NEXT_XFER;
> + else
> + dev->xfers[i].sft = CEC_SIGNAL_FREE_TIME_NEW_INITIATOR;
> + }
> }
>
> -static void vivid_cec_xfer_try_worker(struct work_struct *work)
> +/*
> + * The main emulation of the bus on which CEC adapters attempt to send
> + * messages to each other. The bus keeps track of how long it has been
> + * signal-free and accepts a pending transmission only if the state of
> + * the bus matches the transmission's signal-free requirements. It calls
> + * cec_transmit_attempt_done() for all transmits that enter the bus and
> + * cec_received_msg() for successful transmits.
> + */
> +int vivid_cec_bus_thread(void *_dev)
> {
> - struct vivid_cec_work *cw =
> - container_of(work, struct vivid_cec_work, work.work);
> - struct vivid_dev *dev = cw->dev;
> -
> - spin_lock(&dev->cec_slock);
> - if (dev->cec_xfer_time_jiffies) {
> - list_del(&cw->list);
> - spin_unlock(&dev->cec_slock);
> - cec_transmit_attempt_done(cw->adap, CEC_TX_STATUS_ARB_LOST);
> - kfree(cw);
> - } else {
> - INIT_DELAYED_WORK(&cw->work, vivid_cec_xfer_done_worker);
> - dev->cec_xfer_start_jiffies = jiffies;
> - dev->cec_xfer_time_jiffies = usecs_to_jiffies(cw->usecs);
> - spin_unlock(&dev->cec_slock);
> - schedule_delayed_work(&cw->work, dev->cec_xfer_time_jiffies);
> + u32 last_sft;
> + unsigned int i;
> + unsigned int dest;
> + ktime_t start, end;
> + s64 delta_us, retry_us;
> + unsigned int first_idx;
> + unsigned int first_status;
> + struct vivid_dev *dev = _dev;
> +
> + dev->cec_sft = CEC_SIGNAL_FREE_TIME_NEXT_XFER;
> + for (;;) {
> + bool first = true;
> + int wait_xfer_us = 0;
> + bool valid_dest = false;
> + int wait_arb_lost_us = 0;
> + struct cec_msg first_msg = {};
> + struct xfer_on_bus xfers_on_bus[MAX_OUTPUTS] = {};
> +
> + wait_event_interruptible(dev->kthread_waitq_cec, xfer_ready(dev) ||
> + kthread_should_stop());
> + if (kthread_should_stop())
> + break;
> + last_sft = dev->cec_sft;
> + dev->cec_sft = 0;
> + /*
> + * Move the messages that are ready onto the bus. The adapter with
> + * the most leading zeros will win control of the bus and any other
> + * adapters will lose arbitration.
> + */
> + spin_lock(&dev->cec_xfers_slock);
> + for (i = 0; i < ARRAY_SIZE(dev->xfers); i++) {
> + if (!dev->xfers[i].sft || dev->xfers[i].sft > last_sft)
> + continue;
> + if (first) {
> + first = false;
> + first_idx = i;
> + xfers_on_bus[first_idx].adap = dev->xfers[i].adap;
> + memcpy(first_msg.msg, dev->xfers[i].msg, dev->xfers[i].len);
> + first_msg.len = dev->xfers[i].len;
> + } else {
> + xfers_on_bus[i].adap = dev->xfers[i].adap;
> + xfers_on_bus[i].status = CEC_TX_STATUS_ARB_LOST;
> + /*
> + * For simplicity wait for all 4 bits of the initiator's
> + * address even though HDMI specification uses bit-level
> + * precision.
> + */
> + wait_arb_lost_us = 4 * CEC_DATA_BIT_US + CEC_START_BIT_US;
> + }
> + dev->xfers[i].sft = 0;
> + }
> + dev->last_initiator = cec_msg_initiator(&first_msg);
> + adjust_sfts(dev);
> + spin_unlock(&dev->cec_xfers_slock);
> +
> + dest = cec_msg_destination(&first_msg);
> + valid_dest = cec_msg_is_broadcast(&first_msg);
> + if (!valid_dest)
> + valid_dest = find_dest_adap(dev, xfers_on_bus[first_idx].adap, dest);
> + if (valid_dest) {
> + first_status = CEC_TX_STATUS_OK;
> + /*
> + * Message length is in bytes, but each byte is transmitted in
> + * a block of 10 bits.
> + */
> + wait_xfer_us = first_msg.len * 10 * CEC_DATA_BIT_US;
> + } else {
> + first_status = CEC_TX_STATUS_NACK;
> + /*
> + * A message that is not acknowledged stops transmitting after
> + * the header block of 10 bits.
> + */
> + wait_xfer_us = 10 * CEC_DATA_BIT_US;
> + }
> + wait_xfer_us += CEC_START_BIT_US;
> + xfers_on_bus[first_idx].status = first_status;
I'm getting this compiler warning:
vivid-cec.c:190:3: warning: 'first_idx' may be used uninitialized in this function [-Wmaybe-uninitialized]
The compiler isn't quite smart enough to figure out that first_idx will always be
initialized, but it is still a good idea to just initialize first_idx to 0. I would
also move the first_idx and first_status variables into the for-loop as well, after
the 'bool first' variable.
> +
> + /* Sleep as if sending messages on a real hardware bus. */
> + start = ktime_get();
> + if (wait_arb_lost_us) {
> + usleep_range(wait_arb_lost_us - CEC_MARGIN_US, wait_arb_lost_us);
> + for (i = 0; i < ARRAY_SIZE(xfers_on_bus); i++) {
> + if (xfers_on_bus[i].status != CEC_TX_STATUS_ARB_LOST)
> + continue;
> + cec_transmit_attempt_done(xfers_on_bus[i].adap,
> + CEC_TX_STATUS_ARB_LOST);
> + }
> + if (kthread_should_stop())
> + break;
> + }
> + wait_xfer_us -= wait_arb_lost_us;
> + usleep_range(wait_xfer_us - CEC_MARGIN_US, wait_xfer_us);
> + cec_transmit_attempt_done(xfers_on_bus[first_idx].adap, first_status);
> + if (kthread_should_stop())
> + break;
> + if (first_status == CEC_TX_STATUS_OK) {
> + if (xfers_on_bus[first_idx].adap != dev->cec_rx_adap)
> + cec_received_msg(dev->cec_rx_adap, &first_msg);
> + for (i = 0; i < MAX_OUTPUTS && dev->cec_tx_adap[i]; i++)
> + if (xfers_on_bus[first_idx].adap != dev->cec_tx_adap[i])
> + cec_received_msg(dev->cec_tx_adap[i], &first_msg);
> + }
> + end = ktime_get();
> + /*
> + * If the emulated transfer took more or less time than it should
> + * have, then compensate by adjusting the wait time needed for the
> + * bus to be signal-free for 3 bit periods (the retry time).
> + */
> + delta_us = div_s64(end - start, 1000);
> + delta_us -= wait_xfer_us + wait_arb_lost_us;
> + retry_us = CEC_SIGNAL_FREE_TIME_RETRY * CEC_DATA_BIT_US - delta_us;
> + if (retry_us > CEC_MARGIN_US)
> + usleep_range(retry_us - CEC_MARGIN_US, retry_us);
> + dev->cec_sft = CEC_SIGNAL_FREE_TIME_RETRY;
> + /*
> + * If there are no messages that need to be retried, check if any
> + * adapters that did not just transmit a message are ready to
> + * transmit. If none of these adapters are ready, then increase
> + * the signal-free time so that the bus is available to all
> + * adapters and go back to waiting for a transmission.
> + */
> + while (dev->cec_sft >= CEC_SIGNAL_FREE_TIME_RETRY &&
> + dev->cec_sft < CEC_SIGNAL_FREE_TIME_NEXT_XFER &&
> + !xfer_ready(dev) && !kthread_should_stop()) {
> + usleep_range(2 * CEC_DATA_BIT_US - CEC_MARGIN_US,
> + 2 * CEC_DATA_BIT_US);
> + dev->cec_sft += 2;
> + }
> }
> + return 0;
> }
>
> static int vivid_cec_adap_enable(struct cec_adapter *adap, bool enable)
> @@ -184,41 +238,26 @@ static int vivid_cec_adap_log_addr(struct cec_adapter *adap, u8 log_addr)
> return 0;
> }
>
> -/*
> - * One data bit takes 2400 us, each byte needs 10 bits so that's 24000 us
> - * per byte.
> - */
> -#define USECS_PER_BYTE 24000
> -
> static int vivid_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
> u32 signal_free_time, struct cec_msg *msg)
> {
> struct vivid_dev *dev = cec_get_drvdata(adap);
> - struct vivid_cec_work *cw = kzalloc(sizeof(*cw), GFP_KERNEL);
> - long delta_jiffies = 0;
> -
> - if (cw == NULL)
> - return -ENOMEM;
> - cw->dev = dev;
> - cw->adap = adap;
> - cw->usecs = CEC_FREE_TIME_TO_USEC(signal_free_time) +
> - msg->len * USECS_PER_BYTE;
> - cw->msg = *msg;
> -
> - spin_lock(&dev->cec_slock);
> - list_add(&cw->list, &dev->cec_work_list);
> - if (dev->cec_xfer_time_jiffies == 0) {
> - INIT_DELAYED_WORK(&cw->work, vivid_cec_xfer_done_worker);
> - dev->cec_xfer_start_jiffies = jiffies;
> - dev->cec_xfer_time_jiffies = usecs_to_jiffies(cw->usecs);
> - delta_jiffies = dev->cec_xfer_time_jiffies;
> - } else {
> - INIT_DELAYED_WORK(&cw->work, vivid_cec_xfer_try_worker);
> - delta_jiffies = dev->cec_xfer_start_jiffies +
> - dev->cec_xfer_time_jiffies - jiffies;
> + u8 idx = cec_msg_initiator(msg);
> +
> + spin_lock(&dev->cec_xfers_slock);
> + dev->xfers[idx].adap = adap;
> + memcpy(dev->xfers[idx].msg, msg->msg, CEC_MAX_MSG_SIZE);
> + dev->xfers[idx].len = msg->len;
> + dev->xfers[idx].sft = CEC_SIGNAL_FREE_TIME_RETRY;
> + if (signal_free_time > CEC_SIGNAL_FREE_TIME_RETRY) {
> + if (idx == dev->last_initiator)
> + dev->xfers[idx].sft = CEC_SIGNAL_FREE_TIME_NEXT_XFER;
> + else
> + dev->xfers[idx].sft = CEC_SIGNAL_FREE_TIME_NEW_INITIATOR;
> }
> - spin_unlock(&dev->cec_slock);
> - schedule_delayed_work(&cw->work, delta_jiffies < 0 ? 0 : delta_jiffies);
> + spin_unlock(&dev->cec_xfers_slock);
> + wake_up_interruptible(&dev->kthread_waitq_cec);
> +
> return 0;
> }
>
> diff --git a/drivers/media/test-drivers/vivid/vivid-cec.h b/drivers/media/test-drivers/vivid/vivid-cec.h
> index 7524ed48a914..b2bcddb50b83 100644
> --- a/drivers/media/test-drivers/vivid/vivid-cec.h
> +++ b/drivers/media/test-drivers/vivid/vivid-cec.h
> @@ -9,12 +9,5 @@
> struct cec_adapter *vivid_cec_alloc_adap(struct vivid_dev *dev,
> unsigned int idx,
> bool is_source);
> -void vivid_cec_bus_free_work(struct vivid_dev *dev);
> -
> -#else
> -
> -static inline void vivid_cec_bus_free_work(struct vivid_dev *dev)
> -{
> -}
> -
> +int vivid_cec_bus_thread(void *_dev);
> #endif
> diff --git a/drivers/media/test-drivers/vivid/vivid-core.c b/drivers/media/test-drivers/vivid/vivid-core.c
> index d2bd2653cf54..1973e08953ab 100644
> --- a/drivers/media/test-drivers/vivid/vivid-core.c
> +++ b/drivers/media/test-drivers/vivid/vivid-core.c
> @@ -1878,18 +1878,7 @@ static int vivid_create_instance(struct platform_device *pdev, int inst)
> INIT_LIST_HEAD(&dev->meta_out_active);
> INIT_LIST_HEAD(&dev->touch_cap_active);
>
> - INIT_LIST_HEAD(&dev->cec_work_list);
> - spin_lock_init(&dev->cec_slock);
> - /*
> - * Same as create_singlethread_workqueue, but now I can use the
> - * string formatting of alloc_ordered_workqueue.
> - */
> - dev->cec_workqueue = alloc_ordered_workqueue("vivid-%03d-cec",
> - WQ_MEM_RECLAIM, inst);
> - if (!dev->cec_workqueue) {
> - ret = -ENOMEM;
> - goto unreg_dev;
> - }
> + spin_lock_init(&dev->cec_xfers_slock);
>
> if (allocators[inst] == 1)
> dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
> @@ -1929,6 +1918,18 @@ static int vivid_create_instance(struct platform_device *pdev, int inst)
> cec_tx_bus_cnt++;
> }
> }
> +
> + if (dev->cec_rx_adap || cec_tx_bus_cnt) {
> + init_waitqueue_head(&dev->kthread_waitq_cec);
> + dev->kthread_cec = kthread_run(vivid_cec_bus_thread, dev,
> + "vivid_cec-%s", dev->v4l2_dev.name);
> + if (IS_ERR(dev->kthread_cec)) {
> + dev->kthread_cec = NULL;
> + v4l2_err(&dev->v4l2_dev, "kernel_thread() failed\n");
You should this line here:
ret = PTR_ERR(dev->kthread_cec);
to correctly propagate the kthread_run error code.
Regards,
Hans
> + goto unreg_dev;
> + }
> + }
> +
> #endif
>
> v4l2_ctrl_handler_setup(&dev->ctrl_hdl_vid_cap);
> @@ -1968,10 +1969,8 @@ static int vivid_create_instance(struct platform_device *pdev, int inst)
> cec_unregister_adapter(dev->cec_rx_adap);
> for (i = 0; i < MAX_OUTPUTS; i++)
> cec_unregister_adapter(dev->cec_tx_adap[i]);
> - if (dev->cec_workqueue) {
> - vivid_cec_bus_free_work(dev);
> - destroy_workqueue(dev->cec_workqueue);
> - }
> + if (dev->kthread_cec)
> + kthread_stop(dev->kthread_cec);
> free_dev:
> v4l2_device_put(&dev->v4l2_dev);
> return ret;
> @@ -2093,10 +2092,8 @@ static int vivid_remove(struct platform_device *pdev)
> cec_unregister_adapter(dev->cec_rx_adap);
> for (j = 0; j < MAX_OUTPUTS; j++)
> cec_unregister_adapter(dev->cec_tx_adap[j]);
> - if (dev->cec_workqueue) {
> - vivid_cec_bus_free_work(dev);
> - destroy_workqueue(dev->cec_workqueue);
> - }
> + if (dev->kthread_cec)
> + kthread_stop(dev->kthread_cec);
> v4l2_device_put(&dev->v4l2_dev);
> vivid_devs[i] = NULL;
> }
> diff --git a/drivers/media/test-drivers/vivid/vivid-core.h b/drivers/media/test-drivers/vivid/vivid-core.h
> index 1e3c4f5a9413..45f96706edde 100644
> --- a/drivers/media/test-drivers/vivid/vivid-core.h
> +++ b/drivers/media/test-drivers/vivid/vivid-core.h
> @@ -110,15 +110,11 @@ enum vivid_colorspace {
> #define VIVID_INVALID_SIGNAL(mode) \
> ((mode) == NO_SIGNAL || (mode) == NO_LOCK || (mode) == OUT_OF_RANGE)
>
> -struct vivid_cec_work {
> - struct list_head list;
> - struct delayed_work work;
> +struct vivid_cec_xfer {
> struct cec_adapter *adap;
> - struct vivid_dev *dev;
> - unsigned int usecs;
> - unsigned int timeout_ms;
> - u8 tx_status;
> - struct cec_msg msg;
> + u8 msg[CEC_MAX_MSG_SIZE];
> + u32 len;
> + u32 sft;
> };
>
> struct vivid_dev {
> @@ -560,12 +556,13 @@ struct vivid_dev {
> /* CEC */
> struct cec_adapter *cec_rx_adap;
> struct cec_adapter *cec_tx_adap[MAX_OUTPUTS];
> - struct workqueue_struct *cec_workqueue;
> - spinlock_t cec_slock;
> - struct list_head cec_work_list;
> - unsigned int cec_xfer_time_jiffies;
> - unsigned long cec_xfer_start_jiffies;
> u8 cec_output2bus_map[MAX_OUTPUTS];
> + struct task_struct *kthread_cec;
> + wait_queue_head_t kthread_waitq_cec;
> + struct vivid_cec_xfer xfers[MAX_OUTPUTS];
> + spinlock_t cec_xfers_slock; /* read and write cec messages */
> + u32 cec_sft; /* bus signal free time, in bit periods */
> + u8 last_initiator;
>
> /* CEC OSD String */
> char osd[14];
>
