* [PATCH 2/5] HID: intel_ish-hid: clarify locking in client code
2017-05-16 11:09 [PATCH 0/5] HID: intel_ish-hid: various cleanups Arnd Bergmann
2017-05-16 11:09 ` [PATCH 1/5] HID: intel_ish-hid: fix potential uninitialized data usage Arnd Bergmann
@ 2017-05-16 11:09 ` Arnd Bergmann
2017-05-16 11:09 ` [PATCH 3/5] HID: intel_ish-hid: convert timespec to ktime_t Arnd Bergmann
` (2 subsequent siblings)
4 siblings, 0 replies; 7+ messages in thread
From: Arnd Bergmann @ 2017-05-16 11:09 UTC (permalink / raw)
To: Srinivas Pandruvada, Jiri Kosina; +Cc: linux-input, linux-kernel, arnd
I was trying to understand this code while working on a warning
fix and the locking made no sense: spin_lock_irqsave() is pointless
when run inside of an interrupt handler or nested inside of another
spin_lock_irq() or spin_lock_irqsave().
Here it turned out that the comment above the function is wrong,
as both recv_ishtp_cl_msg_dma() and recv_ishtp_cl_msg() can in fact
be called from a work queue rather than an ISR, so we do have to
use the irqsave() version once.
This fixes the comments accordingly, removes the misleading 'dev_flags'
variable and modifies the inner spinlock to not use 'irqsave'.
No functional change is intended, this is just for readability and
it slightly simplifies the object code.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
drivers/hid/intel-ish-hid/ishtp/client.c | 46 +++++++++++++-------------------
1 file changed, 18 insertions(+), 28 deletions(-)
diff --git a/drivers/hid/intel-ish-hid/ishtp/client.c b/drivers/hid/intel-ish-hid/ishtp/client.c
index 69c9d43612ec..a4511ac8a87f 100644
--- a/drivers/hid/intel-ish-hid/ishtp/client.c
+++ b/drivers/hid/intel-ish-hid/ishtp/client.c
@@ -803,7 +803,7 @@ void ishtp_cl_send_msg(struct ishtp_device *dev, struct ishtp_cl *cl)
* @ishtp_hdr: Pointer to message header
*
* Receive and dispatch ISHTP client messages. This function executes in ISR
- * context
+ * or work queue context
*/
void recv_ishtp_cl_msg(struct ishtp_device *dev,
struct ishtp_msg_hdr *ishtp_hdr)
@@ -813,7 +813,6 @@ void recv_ishtp_cl_msg(struct ishtp_device *dev,
struct ishtp_cl_rb *new_rb;
unsigned char *buffer = NULL;
struct ishtp_cl_rb *complete_rb = NULL;
- unsigned long dev_flags;
unsigned long flags;
int rb_count;
@@ -828,9 +827,9 @@ void recv_ishtp_cl_msg(struct ishtp_device *dev,
goto eoi;
}
- spin_lock_irqsave(&dev->read_list_spinlock, dev_flags);
+ spin_lock_irqsave(&dev->read_list_spinlock, flags);
if (list_empty(&dev->read_list.list)) {
- spin_unlock_irqrestore(&dev->read_list_spinlock, dev_flags);
+ spin_unlock_irqrestore(&dev->read_list_spinlock, flags);
goto eoi;
}
@@ -845,8 +844,7 @@ void recv_ishtp_cl_msg(struct ishtp_device *dev,
/* If no Rx buffer is allocated, disband the rb */
if (rb->buffer.size == 0 || rb->buffer.data == NULL) {
- spin_unlock_irqrestore(&dev->read_list_spinlock,
- dev_flags);
+ spin_unlock_irqrestore(&dev->read_list_spinlock, flags);
dev_err(&cl->device->dev,
"Rx buffer is not allocated.\n");
list_del(&rb->list);
@@ -862,8 +860,7 @@ void recv_ishtp_cl_msg(struct ishtp_device *dev,
* back FC, so communication will be stuck anyway)
*/
if (rb->buffer.size < ishtp_hdr->length + rb->buf_idx) {
- spin_unlock_irqrestore(&dev->read_list_spinlock,
- dev_flags);
+ spin_unlock_irqrestore(&dev->read_list_spinlock, flags);
dev_err(&cl->device->dev,
"message overflow. size %d len %d idx %ld\n",
rb->buffer.size, ishtp_hdr->length,
@@ -889,14 +886,13 @@ void recv_ishtp_cl_msg(struct ishtp_device *dev,
* the whole msg arrived, send a new FC, and add a new
* rb buffer for the next coming msg
*/
- spin_lock_irqsave(&cl->free_list_spinlock, flags);
+ spin_lock(&cl->free_list_spinlock);
if (!list_empty(&cl->free_rb_list.list)) {
new_rb = list_entry(cl->free_rb_list.list.next,
struct ishtp_cl_rb, list);
list_del_init(&new_rb->list);
- spin_unlock_irqrestore(&cl->free_list_spinlock,
- flags);
+ spin_unlock(&cl->free_list_spinlock);
new_rb->cl = cl;
new_rb->buf_idx = 0;
INIT_LIST_HEAD(&new_rb->list);
@@ -905,8 +901,7 @@ void recv_ishtp_cl_msg(struct ishtp_device *dev,
ishtp_hbm_cl_flow_control_req(dev, cl);
} else {
- spin_unlock_irqrestore(&cl->free_list_spinlock,
- flags);
+ spin_unlock(&cl->free_list_spinlock);
}
}
/* One more fragment in message (even if this was last) */
@@ -919,7 +914,7 @@ void recv_ishtp_cl_msg(struct ishtp_device *dev,
break;
}
- spin_unlock_irqrestore(&dev->read_list_spinlock, dev_flags);
+ spin_unlock_irqrestore(&dev->read_list_spinlock, flags);
/* If it's nobody's message, just read and discard it */
if (!buffer) {
uint8_t rd_msg_buf[ISHTP_RD_MSG_BUF_SIZE];
@@ -945,7 +940,7 @@ void recv_ishtp_cl_msg(struct ishtp_device *dev,
* @hbm: hbm buffer
*
* Receive and dispatch ISHTP client messages using DMA. This function executes
- * in ISR context
+ * in ISR or work queue context
*/
void recv_ishtp_cl_msg_dma(struct ishtp_device *dev, void *msg,
struct dma_xfer_hbm *hbm)
@@ -955,12 +950,11 @@ void recv_ishtp_cl_msg_dma(struct ishtp_device *dev, void *msg,
struct ishtp_cl_rb *new_rb;
unsigned char *buffer = NULL;
struct ishtp_cl_rb *complete_rb = NULL;
- unsigned long dev_flags;
unsigned long flags;
- spin_lock_irqsave(&dev->read_list_spinlock, dev_flags);
+ spin_lock_irqsave(&dev->read_list_spinlock, flags);
if (list_empty(&dev->read_list.list)) {
- spin_unlock_irqrestore(&dev->read_list_spinlock, dev_flags);
+ spin_unlock_irqrestore(&dev->read_list_spinlock, flags);
goto eoi;
}
@@ -975,8 +969,7 @@ void recv_ishtp_cl_msg_dma(struct ishtp_device *dev, void *msg,
* If no Rx buffer is allocated, disband the rb
*/
if (rb->buffer.size == 0 || rb->buffer.data == NULL) {
- spin_unlock_irqrestore(&dev->read_list_spinlock,
- dev_flags);
+ spin_unlock_irqrestore(&dev->read_list_spinlock, flags);
dev_err(&cl->device->dev,
"response buffer is not allocated.\n");
list_del(&rb->list);
@@ -992,8 +985,7 @@ void recv_ishtp_cl_msg_dma(struct ishtp_device *dev, void *msg,
* back FC, so communication will be stuck anyway)
*/
if (rb->buffer.size < hbm->msg_length) {
- spin_unlock_irqrestore(&dev->read_list_spinlock,
- dev_flags);
+ spin_unlock_irqrestore(&dev->read_list_spinlock, flags);
dev_err(&cl->device->dev,
"message overflow. size %d len %d idx %ld\n",
rb->buffer.size, hbm->msg_length, rb->buf_idx);
@@ -1017,14 +1009,13 @@ void recv_ishtp_cl_msg_dma(struct ishtp_device *dev, void *msg,
* the whole msg arrived, send a new FC, and add a new
* rb buffer for the next coming msg
*/
- spin_lock_irqsave(&cl->free_list_spinlock, flags);
+ spin_lock(&cl->free_list_spinlock);
if (!list_empty(&cl->free_rb_list.list)) {
new_rb = list_entry(cl->free_rb_list.list.next,
struct ishtp_cl_rb, list);
list_del_init(&new_rb->list);
- spin_unlock_irqrestore(&cl->free_list_spinlock,
- flags);
+ spin_unlock(&cl->free_list_spinlock);
new_rb->cl = cl;
new_rb->buf_idx = 0;
INIT_LIST_HEAD(&new_rb->list);
@@ -1033,8 +1024,7 @@ void recv_ishtp_cl_msg_dma(struct ishtp_device *dev, void *msg,
ishtp_hbm_cl_flow_control_req(dev, cl);
} else {
- spin_unlock_irqrestore(&cl->free_list_spinlock,
- flags);
+ spin_unlock(&cl->free_list_spinlock);
}
/* One more fragment in message (this is always last) */
@@ -1047,7 +1037,7 @@ void recv_ishtp_cl_msg_dma(struct ishtp_device *dev, void *msg,
break;
}
- spin_unlock_irqrestore(&dev->read_list_spinlock, dev_flags);
+ spin_unlock_irqrestore(&dev->read_list_spinlock, flags);
/* If it's nobody's message, just read and discard it */
if (!buffer) {
dev_err(dev->devc, "Dropped Rx (DMA) msg - no request\n");
--
2.9.0
^ permalink raw reply [flat|nested] 7+ messages in thread* [PATCH 3/5] HID: intel_ish-hid: convert timespec to ktime_t
2017-05-16 11:09 [PATCH 0/5] HID: intel_ish-hid: various cleanups Arnd Bergmann
2017-05-16 11:09 ` [PATCH 1/5] HID: intel_ish-hid: fix potential uninitialized data usage Arnd Bergmann
2017-05-16 11:09 ` [PATCH 2/5] HID: intel_ish-hid: clarify locking in client code Arnd Bergmann
@ 2017-05-16 11:09 ` Arnd Bergmann
2017-05-16 11:09 ` [PATCH 4/5] HID: intel_ish-hid: fix format string for size_t Arnd Bergmann
2017-05-16 11:09 ` [PATCH 5/5] HID: intel_ish-hid: enable compile testing Arnd Bergmann
4 siblings, 0 replies; 7+ messages in thread
From: Arnd Bergmann @ 2017-05-16 11:09 UTC (permalink / raw)
To: Srinivas Pandruvada, Jiri Kosina; +Cc: linux-input, linux-kernel, arnd
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@arndb.de>
---
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
^ permalink raw reply [flat|nested] 7+ messages in thread