V4L/DVB (5917): ivtv: improve mailbox responsiveness.
First try polling for the result of a mailbox command, then
switch to a test/sleep loop. Also reduce the sleep time from 10 ms
to 1 ms. Improves the responsiveness of the mailbox handling.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/video/ivtv/ivtv-mailbox.c b/drivers/media/video/ivtv/ivtv-mailbox.c
index 814a673..5e3b679 100644
--- a/drivers/media/video/ivtv/ivtv-mailbox.c
+++ b/drivers/media/video/ivtv/ivtv-mailbox.c
@@ -40,6 +40,7 @@
#define API_HIGH_VOL (1 << 5) /* High volume command (i.e. called during encoding or decoding) */
#define API_NO_WAIT_MB (1 << 4) /* Command may not wait for a free mailbox */
#define API_NO_WAIT_RES (1 << 5) /* Command may not wait for the result */
+#define API_NO_POLL (1 << 6) /* Avoid pointless polling */
struct ivtv_api_info {
int flags; /* Flags, see above */
@@ -51,7 +52,7 @@
static const struct ivtv_api_info api_info[256] = {
/* MPEG encoder API */
API_ENTRY(CX2341X_ENC_PING_FW, API_FAST_RESULT),
- API_ENTRY(CX2341X_ENC_START_CAPTURE, API_RESULT),
+ API_ENTRY(CX2341X_ENC_START_CAPTURE, API_RESULT | API_NO_POLL),
API_ENTRY(CX2341X_ENC_STOP_CAPTURE, API_RESULT),
API_ENTRY(CX2341X_ENC_SET_AUDIO_ID, API_CACHE),
API_ENTRY(CX2341X_ENC_SET_VIDEO_ID, API_CACHE),
@@ -96,7 +97,7 @@
/* MPEG decoder API */
API_ENTRY(CX2341X_DEC_PING_FW, API_FAST_RESULT),
- API_ENTRY(CX2341X_DEC_START_PLAYBACK, API_RESULT),
+ API_ENTRY(CX2341X_DEC_START_PLAYBACK, API_RESULT | API_NO_POLL),
API_ENTRY(CX2341X_DEC_STOP_PLAYBACK, API_RESULT),
API_ENTRY(CX2341X_DEC_SET_PLAYBACK_SPEED, API_RESULT),
API_ENTRY(CX2341X_DEC_STEP_VIDEO, API_RESULT),
@@ -290,6 +291,13 @@
/* Get results */
then = jiffies;
+ if (!(flags & API_NO_POLL)) {
+ /* First try to poll, then switch to delays */
+ for (i = 0; i < 100; i++) {
+ if (readl(&mbox->flags) & IVTV_MBOX_FIRMWARE_DONE)
+ break;
+ }
+ }
while (!(readl(&mbox->flags) & IVTV_MBOX_FIRMWARE_DONE)) {
if (jiffies - then > api_timeout) {
IVTV_DEBUG_WARN("Could not get result (%s)\n", api_info[cmd].name);
@@ -301,7 +309,7 @@
if (flags & API_NO_WAIT_RES)
mdelay(1);
else
- ivtv_msleep_timeout(10, 0);
+ ivtv_msleep_timeout(1, 0);
}
if (jiffies - then > msecs_to_jiffies(100))
IVTV_DEBUG_WARN("%s took %u jiffies\n",