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bnxt_en: Improve the delay logic for firmware response. 

The current code has 2 problems:

1. The maximum wait time is not long enough.  It is about 60% of the
duration specified by the firmware.  It is calling usleep_range(600, 800)
for every 1 msec we are supposed to wait.

2. The granularity of the delay is too coarse.  Many simple firmware
commands finish in 25 usec or less.

We fix these 2 issues by multiplying the original 1 msec loop counter by
40 and calling usleep_range(25, 40) for each iteration.

There is also a second delay loop to wait for the last DMA word to
complete.  This delay loop should be a very short 5 usec wait.

This change results in much faster bring-up/down time:

Before the patch:

time ip link set p4p1 up

real    0m0.120s
user    0m0.001s
sys     0m0.009s

After the patch:

time ip link set p4p1 up

real    0m0.030s
user    0m0.000s
sys     0m0.010s

Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Michael Chan 2016-05-15 03:04:47 -04:00 committed by David S. Miller
parent d0a42d6fc8
commit a11fa2be6d
1 changed files with 10 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
drivers/net/ethernet/broadcom/bnxt/bnxt.c
View File

@ -2780,7 +2780,7 @@ void bnxt_hwrm_cmd_hdr_init(struct bnxt *bp, void *request, u16 req_type,
static int bnxt_hwrm_do_send_msg(struct bnxt *bp, void *msg, u32 msg_len,
int timeout, bool silent)
{
int i, intr_process, rc;
int i, intr_process, rc, tmo_count;
struct input *req = msg;
u32 *data = msg;
__le32 *resp_len, *valid;
@ -2809,11 +2809,12 @@ static int bnxt_hwrm_do_send_msg(struct bnxt *bp, void *msg, u32 msg_len,
timeout = DFLT_HWRM_CMD_TIMEOUT;
i = 0;
tmo_count = timeout * 40;
if (intr_process) {
/* Wait until hwrm response cmpl interrupt is processed */
while (bp->hwrm_intr_seq_id != HWRM_SEQ_ID_INVALID &&
i++ < timeout) {
usleep_range(600, 800);
i++ < tmo_count) {
usleep_range(25, 40);
}
if (bp->hwrm_intr_seq_id != HWRM_SEQ_ID_INVALID) {
@ -2824,15 +2825,15 @@ static int bnxt_hwrm_do_send_msg(struct bnxt *bp, void *msg, u32 msg_len,
} else {
/* Check if response len is updated */
resp_len = bp->hwrm_cmd_resp_addr + HWRM_RESP_LEN_OFFSET;
for (i = 0; i < timeout; i++) {
for (i = 0; i < tmo_count; i++) {
len = (le32_to_cpu(*resp_len) & HWRM_RESP_LEN_MASK) >>
HWRM_RESP_LEN_SFT;
if (len)
break;
usleep_range(600, 800);
usleep_range(25, 40);
}
if (i >= timeout) {
if (i >= tmo_count) {
netdev_err(bp->dev, "Error (timeout: %d) msg {0x%x 0x%x} len:%d\n",
timeout, le16_to_cpu(req->req_type),
le16_to_cpu(req->seq_id), *resp_len);
@ -2841,13 +2842,13 @@ static int bnxt_hwrm_do_send_msg(struct bnxt *bp, void *msg, u32 msg_len,
/* Last word of resp contains valid bit */
valid = bp->hwrm_cmd_resp_addr + len - 4;
for (i = 0; i < timeout; i++) {
for (i = 0; i < 5; i++) {
if (le32_to_cpu(*valid) & HWRM_RESP_VALID_MASK)
break;
usleep_range(600, 800);
udelay(1);
}
if (i >= timeout) {
if (i >= 5) {
netdev_err(bp->dev, "Error (timeout: %d) msg {0x%x 0x%x} len:%d v:%d\n",
timeout, le16_to_cpu(req->req_type),
le16_to_cpu(req->seq_id), len, *valid);