V4L/DVB (9727): cx18: Adjust outgoing mailbox timeouts and remove statistics logging

cx18: Adjust outgoing mailbox timeouts and remove statistics logging.
This saves some wasted storage in struct cx18 for each card.  Cutting
the outgoing mailbox timeouts in half from the previous value appears to
be safe with MythTV.  Got rid of interrupted case code path after
a wait uninterruptable returns.

Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 8 insertions, 25 deletions

diff --git a/drivers/media/video/cx18/cx18-mailbox.c b/drivers/media/video/cx18/cx18-mailbox.c
index abd39aaa345c..79647c6d6c55 100644
--- a/drivers/media/video/cx18/cx18-mailbox.c
+++ b/drivers/media/video/cx18/cx18-mailbox.c
@@ -462,13 +462,6 @@ void cx18_api_epu_cmd_irq(struct cx18 *cx, int rpu)
  * Functions called from a non-interrupt, non work_queue context
  */
 
-static void cx18_api_log_ack_delay(struct cx18 *cx, int msecs)
-{
-	if (msecs > CX18_MAX_MB_ACK_DELAY)
-		msecs = CX18_MAX_MB_ACK_DELAY;
-	atomic_inc(&cx->mbox_stats.mb_ack_delay[msecs]);
-}
-
 static int cx18_api_call(struct cx18 *cx, u32 cmd, int args, u32 data[])
 {
 	const struct cx18_api_info *info = find_api_info(cmd);
@@ -523,7 +516,7 @@ static int cx18_api_call(struct cx18 *cx, u32 cmd, int args, u32 data[])
 	 */
 	state = cx18_readl(cx, xpu_state);
 	req = cx18_readl(cx, &mb->request);
-	timeout = msecs_to_jiffies(20); /* 1 field at 50 Hz vertical refresh */
+	timeout = msecs_to_jiffies(10);
 	ret = wait_event_timeout(*waitq,
 				 (ack = cx18_readl(cx, &mb->ack)) == req,
 				 timeout);
@@ -533,8 +526,8 @@ static int cx18_api_call(struct cx18 *cx, u32 cmd, int args, u32 data[])
 		CX18_ERR("mbox was found stuck busy when setting up for %s; "
 			 "clearing busy and trying to proceed\n", info->name);
 	} else if (ret != timeout)
-		CX18_DEBUG_API("waited %u usecs for busy mbox to be acked\n",
-			       jiffies_to_usecs(timeout-ret));
+		CX18_DEBUG_API("waited %u msecs for busy mbox to be acked\n",
+			       jiffies_to_msecs(timeout-ret));
 
 	/* Build the outgoing mailbox */
 	req = ((req & 0xfffffffe) == 0xfffffffe) ? 1 : req + 1;
@@ -548,10 +541,8 @@ static int cx18_api_call(struct cx18 *cx, u32 cmd, int args, u32 data[])
 
 	/*
 	 * Notify the XPU and wait for it to send an Ack back
-	 * 21 ms = ~ 0.5 frames at a frame rate of 24 fps
-	 * 42 ms = ~ 1 frame at a frame rate of 24 fps
 	 */
-	timeout = msecs_to_jiffies((info->flags & API_FAST) ? 21 : 42);
+	timeout = msecs_to_jiffies((info->flags & API_FAST) ? 10 : 20);
 
 	CX18_DEBUG_HI_IRQ("sending interrupt SW1: %x to send %s\n",
 			  irq, info->name);
@@ -561,27 +552,19 @@ static int cx18_api_call(struct cx18 *cx, u32 cmd, int args, u32 data[])
 		       *waitq,
 		       cx18_readl(cx, &mb->ack) == cx18_readl(cx, &mb->request),
 		       timeout);
+
 	if (ret == 0) {
 		/* Timed out */
 		mutex_unlock(mb_lock);
-		i = jiffies_to_msecs(timeout);
-		cx18_api_log_ack_delay(cx, i);
 		CX18_WARN("sending %s timed out waiting %d msecs for RPU "
-			  "acknowledgement\n", info->name, i);
+			  "acknowledgement\n",
+			  info->name, jiffies_to_msecs(timeout));
 		return -EINVAL;
-	} else if (ret < 0) {
-		/* Interrupted */
-		mutex_unlock(mb_lock);
-		CX18_WARN("sending %s was interrupted waiting for RPU"
-			  "acknowledgement\n", info->name);
-		return -EINTR;
 	}
 
-	i = jiffies_to_msecs(timeout-ret);
-	cx18_api_log_ack_delay(cx, i);
 	if (ret != timeout)
 		CX18_DEBUG_HI_API("waited %u msecs for %s to be acked\n",
-				  i, info->name);
+				  jiffies_to_msecs(timeout-ret), info->name);
 
 	/* Collect data returned by the XPU */
 	for (i = 0; i < MAX_MB_ARGUMENTS; i++)