media: vivid: use ktime_t for timestamp calculation

timespec is generally deprecated because of the y2038 overflow.
In vivid, the usage is fine, since we are dealing with monotonic
timestamps, but we can also simplify the code by going to ktime_t.

Using ktime_divns() should be roughly as efficient as the old code,
since the constant 64-bit division gets turned into a multiplication
on modern platforms, and we save multiple 32-bit divisions that can be
expensive e.g. on ARMv7.

Tested-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

diff --git a/drivers/media/platform/vivid/vivid-core.c b/drivers/media/platform/vivid/vivid-core.c
index 5f316a5e38dbe061d14fda0da3c321046327c439..a091cfd931648661e63f4947d0e0c7917bf151e6 100644 (file)
--- a/drivers/media/platform/vivid/vivid-core.c
+++ b/drivers/media/platform/vivid/vivid-core.c
@@ -995,7 +995,7 @@ static int vivid_create_instance(struct platform_device *pdev, int inst)
 
        dev->edid_max_blocks = dev->edid_blocks = 2;
        memcpy(dev->edid, vivid_hdmi_edid, sizeof(vivid_hdmi_edid));
-       ktime_get_ts(&dev->radio_rds_init_ts);
+       dev->radio_rds_init_time = ktime_get();
 
        /* create all controls */
        ret = vivid_create_controls(dev, ccs_cap == -1, ccs_out == -1, no_error_inj,

diff --git a/drivers/media/platform/vivid/vivid-core.h b/drivers/media/platform/vivid/vivid-core.h
index 5cdf95bdc4d16af43338faf3b7a545ac5603259d..d8bff4dcefb705cacc3e22f0df163b22f0fe17c8 100644 (file)
--- a/drivers/media/platform/vivid/vivid-core.h
+++ b/drivers/media/platform/vivid/vivid-core.h
@@ -510,7 +510,7 @@ struct vivid_dev {
 
        /* Shared between radio receiver and transmitter */
        bool                            radio_rds_loop;
-       struct timespec                 radio_rds_init_ts;
+       ktime_t                         radio_rds_init_time;
 
        /* CEC */
        struct cec_adapter              *cec_rx_adap;

diff --git a/drivers/media/platform/vivid/vivid-radio-rx.c b/drivers/media/platform/vivid/vivid-radio-rx.c
index 47c36c26096b206dae3bd1af37b52a126d324c3d..35fbff4905358a5b6fe47fc7409781166e93de20 100644 (file)
--- a/drivers/media/platform/vivid/vivid-radio-rx.c
+++ b/drivers/media/platform/vivid/vivid-radio-rx.c
@@ -38,9 +38,9 @@ ssize_t vivid_radio_rx_read(struct file *file, char __user *buf,
                         size_t size, loff_t *offset)
 {
        struct vivid_dev *dev = video_drvdata(file);
-       struct timespec ts;
        struct v4l2_rds_data *data = dev->rds_gen.data;
        bool use_alternates;
+       ktime_t timestamp;
        unsigned blk;
        int perc;
        int i;
@@ -64,17 +64,16 @@ ssize_t vivid_radio_rx_read(struct file *file, char __user *buf,
        }
 
 retry:
-       ktime_get_ts(&ts);
-       use_alternates = ts.tv_sec % 10 >= 5;
+       timestamp = ktime_sub(ktime_get(), dev->radio_rds_init_time);
+       blk = ktime_divns(timestamp, VIVID_RDS_NSEC_PER_BLK);
+       use_alternates = (blk % VIVID_RDS_GEN_BLOCKS) & 1;
+
        if (dev->radio_rx_rds_last_block == 0 ||
            dev->radio_rx_rds_use_alternates != use_alternates) {
                dev->radio_rx_rds_use_alternates = use_alternates;
                /* Re-init the RDS generator */
                vivid_radio_rds_init(dev);
        }
-       ts = timespec_sub(ts, dev->radio_rds_init_ts);
-       blk = ts.tv_sec * 100 + ts.tv_nsec / 10000000;
-       blk = (blk * VIVID_RDS_GEN_BLOCKS) / 500;
        if (blk >= dev->radio_rx_rds_last_block + VIVID_RDS_GEN_BLOCKS)
                dev->radio_rx_rds_last_block = blk - VIVID_RDS_GEN_BLOCKS + 1;
 

diff --git a/drivers/media/platform/vivid/vivid-radio-tx.c b/drivers/media/platform/vivid/vivid-radio-tx.c
index 0e8025b7b4dde40ebd4972c0238c65a4201e9449..897b56195ca7a778e098f5c88e00fe4b6766756d 100644 (file)
--- a/drivers/media/platform/vivid/vivid-radio-tx.c
+++ b/drivers/media/platform/vivid/vivid-radio-tx.c
@@ -37,7 +37,7 @@ ssize_t vivid_radio_tx_write(struct file *file, const char __user *buf,
 {
        struct vivid_dev *dev = video_drvdata(file);
        struct v4l2_rds_data *data = dev->rds_gen.data;
-       struct timespec ts;
+       ktime_t timestamp;
        unsigned blk;
        int i;
 
@@ -58,10 +58,8 @@ ssize_t vivid_radio_tx_write(struct file *file, const char __user *buf,
        dev->radio_tx_rds_owner = file->private_data;
 
 retry:
-       ktime_get_ts(&ts);
-       ts = timespec_sub(ts, dev->radio_rds_init_ts);
-       blk = ts.tv_sec * 100 + ts.tv_nsec / 10000000;
-       blk = (blk * VIVID_RDS_GEN_BLOCKS) / 500;
+       timestamp = ktime_sub(ktime_get(), dev->radio_rds_init_time);
+       blk = ktime_divns(timestamp, VIVID_RDS_NSEC_PER_BLK);
        if (blk - VIVID_RDS_GEN_BLOCKS >= dev->radio_tx_rds_last_block)
                dev->radio_tx_rds_last_block = blk - VIVID_RDS_GEN_BLOCKS + 1;
 

diff --git a/drivers/media/platform/vivid/vivid-rds-gen.h b/drivers/media/platform/vivid/vivid-rds-gen.h
index eff4bf552ed3686765584a8d16cfe3d08611f64f..e55e3b22b7ca409c20e2dd06a9e94017676fcbbd 100644 (file)
--- a/drivers/media/platform/vivid/vivid-rds-gen.h
+++ b/drivers/media/platform/vivid/vivid-rds-gen.h
@@ -29,6 +29,7 @@
 #define VIVID_RDS_GEN_GROUPS 57
 #define VIVID_RDS_GEN_BLKS_PER_GRP 4
 #define VIVID_RDS_GEN_BLOCKS (VIVID_RDS_GEN_BLKS_PER_GRP * VIVID_RDS_GEN_GROUPS)
+#define VIVID_RDS_NSEC_PER_BLK (u32)(5ull * NSEC_PER_SEC / VIVID_RDS_GEN_BLOCKS)
 
 struct vivid_rds_gen {
        struct v4l2_rds_data    data[VIVID_RDS_GEN_BLOCKS];