2016-12-05 15:47:15

by Shiva Kerdel

Subject: [PATCH 1/2] Staging: dgnc: dgnc_cls.c: Use usleep_range over udelay to improve coalescing processor wakeups

In most cases, usleep_range is better than udelay, as the precise wakeup
from udelay is unnecessary.

usleep_range gives a much better chance of coalescing processor wakeups.

Signed-off-by: Shiva Kerdel <[email protected]>
---
drivers/staging/dgnc/dgnc_cls.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/dgnc/dgnc_cls.c b/drivers/staging/dgnc/dgnc_cls.c
index c20ffdd..6607243a 100644
--- a/drivers/staging/dgnc/dgnc_cls.c
+++ b/drivers/staging/dgnc/dgnc_cls.c
@@ -409,7 +409,7 @@ static void cls_assert_modem_signals(struct channel_t *ch)
writeb(out, &ch->ch_cls_uart->mcr);

/* Give time for the UART to actually drop the signals */
- udelay(10);
+ usleep_range(10, 20);
}

static void cls_copy_data_from_queue_to_uart(struct channel_t *ch)
@@ -631,7 +631,7 @@ static void cls_flush_uart_read(struct channel_t *ch)
* Presumably, this is a bug in this UART.
*/

- udelay(10);
+ usleep_range(10, 20);
}

/*
@@ -1096,7 +1096,7 @@ static void cls_uart_init(struct channel_t *ch)

writeb(UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT,
&ch->ch_cls_uart->isr_fcr);
- udelay(10);
+ usleep_range(10, 20);

ch->ch_flags |= (CH_FIFO_ENABLED | CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);

--
2.10.2

2016-12-05 15:47:19

by Shiva Kerdel

Subject: [PATCH 2/2] Staging: dgnc: dgnc_neo.c: Use usleep_range over udelay to improve coalescing processor wakeups

In most cases, usleep_range is better than udelay, as the precise wakeup
from udelay is unnecessary.

usleep_range gives a much better chance of coalescing processor wakeups.

Signed-off-by: Shiva Kerdel <[email protected]>
---
drivers/staging/dgnc/dgnc_neo.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/staging/dgnc/dgnc_neo.c b/drivers/staging/dgnc/dgnc_neo.c
index 3eefefe..20bc271 100644
--- a/drivers/staging/dgnc/dgnc_neo.c
+++ b/drivers/staging/dgnc/dgnc_neo.c
@@ -1352,7 +1352,7 @@ static void neo_flush_uart_write(struct channel_t *ch)
*/
tmp = readb(&ch->ch_neo_uart->isr_fcr);
if (tmp & 4)
- udelay(10);
+ usleep_range(10, 20);
else
break;
}
@@ -1384,7 +1384,7 @@ static void neo_flush_uart_read(struct channel_t *ch)
*/
tmp = readb(&ch->ch_neo_uart->isr_fcr);
if (tmp & 2)
- udelay(10);
+ usleep_range(10, 20);
else
break;
}
@@ -1616,7 +1616,7 @@ static void neo_assert_modem_signals(struct channel_t *ch)
neo_pci_posting_flush(ch->ch_bd);

/* Give time for the UART to actually raise/drop the signals */
- udelay(10);
+ usleep_range(10, 20);
}

static void neo_send_start_character(struct channel_t *ch)
@@ -1628,7 +1628,7 @@ static void neo_send_start_character(struct channel_t *ch)
ch->ch_xon_sends++;
writeb(ch->ch_startc, &ch->ch_neo_uart->txrx);
neo_pci_posting_flush(ch->ch_bd);
- udelay(10);
+ usleep_range(10, 20);
}
}

@@ -1641,7 +1641,7 @@ static void neo_send_stop_character(struct channel_t *ch)
ch->ch_xoff_sends++;
writeb(ch->ch_stopc, &ch->ch_neo_uart->txrx);
neo_pci_posting_flush(ch->ch_bd);
- udelay(10);
+ usleep_range(10, 20);
}
}

--
2.10.2