From 464254e5dbd60124936d47be6679a23b42840b51 Mon Sep 17 00:00:00 2001 From: Heiner Kallweit Date: Fri, 27 Nov 2015 20:02:38 -0200 Subject: [PATCH] [media] media: rc: raw: improve FIFO handling The FIFO is used for ir_raw_event records, however for some historic reason the FIFO is used on a per byte basis. IMHO this adds unneeded complexity. Therefore set up the FIFO for ir_raw_event records. This also allows to define the FIFO statically as part of ir_raw_event_ctrl instead of having to allocate the FIFO dynamically. In addition: - When writing into the FIFO and it's full return ENOSPC instead of ENOMEM thus making it easier to tell between "FIFO full" and "Dynamic memory allocation failed" when the error is propagated to a higher level. Also add an error message. - When reading from the FIFO check whether it's empty. This is not strictly needed here but kfifo_out is annotated "must check" anyway. Successfully tested it with the nuvoton-cir driver. Signed-off-by: Heiner Kallweit Signed-off-by: Mauro Carvalho Chehab --- drivers/media/rc/rc-core-priv.h | 6 +++++- drivers/media/rc/rc-ir-raw.c | 23 ++++++++--------------- 2 files changed, 13 insertions(+), 16 deletions(-) diff --git a/drivers/media/rc/rc-core-priv.h b/drivers/media/rc/rc-core-priv.h index 7359f3d03b64..585d5e52118d 100644 --- a/drivers/media/rc/rc-core-priv.h +++ b/drivers/media/rc/rc-core-priv.h @@ -16,6 +16,9 @@ #ifndef _RC_CORE_PRIV #define _RC_CORE_PRIV +/* Define the max number of pulse/space transitions to buffer */ +#define MAX_IR_EVENT_SIZE 512 + #include #include #include @@ -35,7 +38,8 @@ struct ir_raw_event_ctrl { struct list_head list; /* to keep track of raw clients */ struct task_struct *thread; spinlock_t lock; - struct kfifo_rec_ptr_1 kfifo; /* fifo for the pulse/space durations */ + /* fifo for the pulse/space durations */ + DECLARE_KFIFO(kfifo, struct ir_raw_event, MAX_IR_EVENT_SIZE); ktime_t last_event; /* when last event occurred */ enum raw_event_type last_type; /* last event type */ struct rc_dev *dev; /* pointer to the parent rc_dev */ diff --git a/drivers/media/rc/rc-ir-raw.c b/drivers/media/rc/rc-ir-raw.c index c69807fe2fef..144304c94606 100644 --- a/drivers/media/rc/rc-ir-raw.c +++ b/drivers/media/rc/rc-ir-raw.c @@ -20,9 +20,6 @@ #include #include "rc-core-priv.h" -/* Define the max number of pulse/space transitions to buffer */ -#define MAX_IR_EVENT_SIZE 512 - /* Used to keep track of IR raw clients, protected by ir_raw_handler_lock */ static LIST_HEAD(ir_raw_client_list); @@ -36,14 +33,12 @@ static int ir_raw_event_thread(void *data) struct ir_raw_event ev; struct ir_raw_handler *handler; struct ir_raw_event_ctrl *raw = (struct ir_raw_event_ctrl *)data; - int retval; while (!kthread_should_stop()) { spin_lock_irq(&raw->lock); - retval = kfifo_len(&raw->kfifo); - if (retval < sizeof(ev)) { + if (!kfifo_len(&raw->kfifo)) { set_current_state(TASK_INTERRUPTIBLE); if (kthread_should_stop()) @@ -54,7 +49,8 @@ static int ir_raw_event_thread(void *data) continue; } - retval = kfifo_out(&raw->kfifo, &ev, sizeof(ev)); + if(!kfifo_out(&raw->kfifo, &ev, 1)) + dev_err(&raw->dev->dev, "IR event FIFO is empty!\n"); spin_unlock_irq(&raw->lock); mutex_lock(&ir_raw_handler_lock); @@ -87,8 +83,10 @@ int ir_raw_event_store(struct rc_dev *dev, struct ir_raw_event *ev) IR_dprintk(2, "sample: (%05dus %s)\n", TO_US(ev->duration), TO_STR(ev->pulse)); - if (kfifo_in(&dev->raw->kfifo, ev, sizeof(*ev)) != sizeof(*ev)) - return -ENOMEM; + if (!kfifo_put(&dev->raw->kfifo, *ev)) { + dev_err(&dev->dev, "IR event FIFO is full!\n"); + return -ENOSPC; + } return 0; } @@ -273,11 +271,7 @@ int ir_raw_event_register(struct rc_dev *dev) dev->raw->dev = dev; dev->change_protocol = change_protocol; - rc = kfifo_alloc(&dev->raw->kfifo, - sizeof(struct ir_raw_event) * MAX_IR_EVENT_SIZE, - GFP_KERNEL); - if (rc < 0) - goto out; + INIT_KFIFO(dev->raw->kfifo); spin_lock_init(&dev->raw->lock); dev->raw->thread = kthread_run(ir_raw_event_thread, dev->raw, @@ -319,7 +313,6 @@ void ir_raw_event_unregister(struct rc_dev *dev) handler->raw_unregister(dev); mutex_unlock(&ir_raw_handler_lock); - kfifo_free(&dev->raw->kfifo); kfree(dev->raw); dev->raw = NULL; } -- 2.39.5