[PATCH 3/5] HID: intel_ish-hid: convert timespec to ktime_t

From: Arnd Bergmann
Date: Tue May 16 2017 - 07:10:40 EST


The internal accounting uses 'timespec' based time stamps, which is
slightly inefficient and also problematic once we get to the time_t
overflow in 2038.

When communicating to the firmware, we even get an open-coded 64-bit
division that prevents the code from being build-tested on 32-bit
architectures and is inefficient due to the double conversion from
64-bit nanoseconds to seconds+nanoseconds and then microseconds.

This changes the code to use ktime_t instead.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/hid/intel-ish-hid/ipc/ipc.c | 15 ++++-----------
drivers/hid/intel-ish-hid/ishtp/client.c | 4 ++--
drivers/hid/intel-ish-hid/ishtp/client.h | 6 +++---
drivers/hid/intel-ish-hid/ishtp/hbm.c | 11 ++++-------
4 files changed, 13 insertions(+), 23 deletions(-)

diff --git a/drivers/hid/intel-ish-hid/ipc/ipc.c b/drivers/hid/intel-ish-hid/ipc/ipc.c
index 842d8416a7a6..9a60ec13cb10 100644
--- a/drivers/hid/intel-ish-hid/ipc/ipc.c
+++ b/drivers/hid/intel-ish-hid/ipc/ipc.c
@@ -296,17 +296,12 @@ static int write_ipc_from_queue(struct ishtp_device *dev)
/* If sending MNG_SYNC_FW_CLOCK, update clock again */
if (IPC_HEADER_GET_PROTOCOL(doorbell_val) == IPC_PROTOCOL_MNG &&
IPC_HEADER_GET_MNG_CMD(doorbell_val) == MNG_SYNC_FW_CLOCK) {
- struct timespec ts_system;
- struct timeval tv_utc;
- uint64_t usec_system, usec_utc;
+ uint64_t usec_system, usec_utc;
struct ipc_time_update_msg time_update;
struct time_sync_format ts_format;

- get_monotonic_boottime(&ts_system);
- do_gettimeofday(&tv_utc);
- usec_system = (timespec_to_ns(&ts_system)) / NSEC_PER_USEC;
- usec_utc = (uint64_t)tv_utc.tv_sec * 1000000 +
- ((uint32_t)tv_utc.tv_usec);
+ usec_system = ktime_to_us(ktime_get_boottime());
+ usec_utc = ktime_to_us(ktime_get_real());
ts_format.ts1_source = HOST_SYSTEM_TIME_USEC;
ts_format.ts2_source = HOST_UTC_TIME_USEC;
ts_format.reserved = 0;
@@ -575,15 +570,13 @@ static void fw_reset_work_fn(struct work_struct *unused)
static void _ish_sync_fw_clock(struct ishtp_device *dev)
{
static unsigned long prev_sync;
- struct timespec ts;
uint64_t usec;

if (prev_sync && jiffies - prev_sync < 20 * HZ)
return;

prev_sync = jiffies;
- get_monotonic_boottime(&ts);
- usec = (timespec_to_ns(&ts)) / NSEC_PER_USEC;
+ usec = ktime_to_us(ktime_get_boottime());
ipc_send_mng_msg(dev, MNG_SYNC_FW_CLOCK, &usec, sizeof(uint64_t));
}

diff --git a/drivers/hid/intel-ish-hid/ishtp/client.c b/drivers/hid/intel-ish-hid/ishtp/client.c
index a4511ac8a87f..6cb78c29d111 100644
--- a/drivers/hid/intel-ish-hid/ishtp/client.c
+++ b/drivers/hid/intel-ish-hid/ishtp/client.c
@@ -925,7 +925,7 @@ void recv_ishtp_cl_msg(struct ishtp_device *dev,
}

if (complete_rb) {
- getnstimeofday(&cl->ts_rx);
+ cl->ts_rx = ktime_get();
++cl->recv_msg_cnt_ipc;
ishtp_cl_read_complete(complete_rb);
}
@@ -1045,7 +1045,7 @@ void recv_ishtp_cl_msg_dma(struct ishtp_device *dev, void *msg,
}

if (complete_rb) {
- getnstimeofday(&cl->ts_rx);
+ cl->ts_rx = ktime_get();
++cl->recv_msg_cnt_dma;
ishtp_cl_read_complete(complete_rb);
}
diff --git a/drivers/hid/intel-ish-hid/ishtp/client.h b/drivers/hid/intel-ish-hid/ishtp/client.h
index 444d069c2ed4..79eade547f5d 100644
--- a/drivers/hid/intel-ish-hid/ishtp/client.h
+++ b/drivers/hid/intel-ish-hid/ishtp/client.h
@@ -118,9 +118,9 @@ struct ishtp_cl {
unsigned int out_flow_ctrl_cnt;

/* Rx msg ... out FC timing */
- struct timespec ts_rx;
- struct timespec ts_out_fc;
- struct timespec ts_max_fc_delay;
+ ktime_t ts_rx;
+ ktime_t ts_out_fc;
+ ktime_t ts_max_fc_delay;
void *client_data;
};

diff --git a/drivers/hid/intel-ish-hid/ishtp/hbm.c b/drivers/hid/intel-ish-hid/ishtp/hbm.c
index b7213608ce43..ae4a69f7f2f4 100644
--- a/drivers/hid/intel-ish-hid/ishtp/hbm.c
+++ b/drivers/hid/intel-ish-hid/ishtp/hbm.c
@@ -321,13 +321,10 @@ int ishtp_hbm_cl_flow_control_req(struct ishtp_device *dev,
if (!rv) {
++cl->out_flow_ctrl_creds;
++cl->out_flow_ctrl_cnt;
- getnstimeofday(&cl->ts_out_fc);
- if (cl->ts_rx.tv_sec && cl->ts_rx.tv_nsec) {
- struct timespec ts_diff;
-
- ts_diff = timespec_sub(cl->ts_out_fc, cl->ts_rx);
- if (timespec_compare(&ts_diff, &cl->ts_max_fc_delay)
- > 0)
+ cl->ts_out_fc = ktime_get();
+ if (cl->ts_rx) {
+ ktime_t ts_diff = ktime_sub(cl->ts_out_fc, cl->ts_rx);
+ if (ktime_after(ts_diff, cl->ts_max_fc_delay))
cl->ts_max_fc_delay = ts_diff;
}
} else {
--
2.9.0