From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Antonino A. Daplas" Subject: [PATCH 2/9] intelfb: Fix ring space calculation Date: Sun, 25 Feb 2007 16:50:56 +0800 Message-ID: <1172393456.16179.30.camel@daplas> Reply-To: linux-fbdev-devel@lists.sourceforge.net Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============0737783515==" Return-path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.92] helo=mail.sourceforge.net) by sc8-sf-list1-new.sourceforge.net with esmtp (Exim 4.43) id 1HLFOr-00075A-HZ for linux-fbdev-devel@lists.sourceforge.net; Sun, 25 Feb 2007 01:10:33 -0800 Received: from py-out-1112.google.com ([64.233.166.178]) by mail.sourceforge.net with esmtp (Exim 4.44) id 1HLFOr-0005hh-1o for linux-fbdev-devel@lists.sourceforge.net; Sun, 25 Feb 2007 01:10:33 -0800 Received: by py-out-1112.google.com with SMTP id a29so528629pyi for ; Sun, 25 Feb 2007 01:10:32 -0800 (PST) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-fbdev-devel-bounces@lists.sourceforge.net Errors-To: linux-fbdev-devel-bounces@lists.sourceforge.net To: Andrew Morton Cc: Dave Airlie , "Orczykowski, Juergen" , Linux Fbdev development list --===============0737783515== Content-Type: multipart/alternative; boundary="=-g1C5QBdqT/tZm2O+IaHT" --=-g1C5QBdqT/tZm2O+IaHT Content-Type: text/plain Content-Transfer-Encoding: 7bit From: Orczykowski, Juergen If there is less then RING_MIN_FREE available in the ring buffer, dinfo->ring_space is set to a big value forcing wait_ring to return. Fix by making ring space = 0 if ring space < RING_MIN_FREE. Signed-off-by: Antonino Daplas --- drivers/video/intelfb/intelfbhw.c | 34 +++++++++++++++++++++------------- 1 files changed, 21 insertions(+), 13 deletions(-) diff --git a/drivers/video/intelfb/intelfbhw.c b/drivers/video/intelfb/intelfbhw.c index c1eb18b..16bc8d7 100644 --- a/drivers/video/intelfb/intelfbhw.c +++ b/drivers/video/intelfb/intelfbhw.c @@ -1428,6 +1428,24 @@ static void refresh_ring(struct intelfb_ static void reset_state(struct intelfb_info *dinfo); static void do_flush(struct intelfb_info *dinfo); +static u32 get_ring_space(struct intelfb_info *dinfo) +{ + u32 ring_space; + + if (dinfo->ring_tail >= dinfo->ring_head) + ring_space = dinfo->ring.size - + (dinfo->ring_tail - dinfo->ring_head); + else + ring_space = dinfo->ring_head - dinfo->ring_tail; + + if (ring_space > RING_MIN_FREE) + ring_space -= RING_MIN_FREE; + else + ring_space = 0; + + return ring_space; +} + static int wait_ring(struct intelfb_info *dinfo, int n) { @@ -1442,13 +1460,8 @@ #endif end = jiffies + (HZ * 3); while (dinfo->ring_space < n) { dinfo->ring_head = INREG(PRI_RING_HEAD) & RING_HEAD_MASK; - if (dinfo->ring_tail + RING_MIN_FREE < dinfo->ring_head) - dinfo->ring_space = dinfo->ring_head - - (dinfo->ring_tail + RING_MIN_FREE); - else - dinfo->ring_space = (dinfo->ring.size + - dinfo->ring_head) - - (dinfo->ring_tail + RING_MIN_FREE); + dinfo->ring_space = get_ring_space(dinfo); + if (dinfo->ring_head != last_head) { end = jiffies + (HZ * 3); last_head = dinfo->ring_head; @@ -1513,12 +1526,7 @@ #endif dinfo->ring_head = INREG(PRI_RING_HEAD) & RING_HEAD_MASK; dinfo->ring_tail = INREG(PRI_RING_TAIL) & RING_TAIL_MASK; - if (dinfo->ring_tail + RING_MIN_FREE < dinfo->ring_head) - dinfo->ring_space = dinfo->ring_head - - (dinfo->ring_tail + RING_MIN_FREE); - else - dinfo->ring_space = (dinfo->ring.size + dinfo->ring_head) - - (dinfo->ring_tail + RING_MIN_FREE); + dinfo->ring_space = get_ring_space(dinfo); } static void --=-g1C5QBdqT/tZm2O+IaHT Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: 7bit 
From: Orczykowski, Juergen <juergen.orczykowski@siemens.com>

If there is less then RING_MIN_FREE available in the ring buffer,
dinfo->ring_space is set to a big value forcing wait_ring to return.

Fix by making ring space = 0 if ring space < RING_MIN_FREE.

Signed-off-by: Antonino Daplas <adaplas@gmail.com>
---

 drivers/video/intelfb/intelfbhw.c |   34 +++++++++++++++++++++-------------
 1 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/drivers/video/intelfb/intelfbhw.c b/drivers/video/intelfb/intelfbhw.c
index c1eb18b..16bc8d7 100644
--- a/drivers/video/intelfb/intelfbhw.c
+++ b/drivers/video/intelfb/intelfbhw.c
@@ -1428,6 +1428,24 @@ static void refresh_ring(struct intelfb_
 static void reset_state(struct intelfb_info *dinfo);
 static void do_flush(struct intelfb_info *dinfo);
 
+static  u32 get_ring_space(struct intelfb_info *dinfo)
+{
+	u32 ring_space;
+
+	if (dinfo->ring_tail >= dinfo->ring_head)
+		ring_space = dinfo->ring.size -
+			(dinfo->ring_tail - dinfo->ring_head);
+	else
+		ring_space = dinfo->ring_head - dinfo->ring_tail;
+
+	if (ring_space > RING_MIN_FREE)
+		ring_space -= RING_MIN_FREE;
+	else
+		ring_space = 0;
+
+	return ring_space;
+}
+
 static int
 wait_ring(struct intelfb_info *dinfo, int n)
 {
@@ -1442,13 +1460,8 @@ #endif
 	end = jiffies + (HZ * 3);
 	while (dinfo->ring_space < n) {
 		dinfo->ring_head = INREG(PRI_RING_HEAD) & RING_HEAD_MASK;
-		if (dinfo->ring_tail + RING_MIN_FREE < dinfo->ring_head)
-			dinfo->ring_space = dinfo->ring_head
-				- (dinfo->ring_tail + RING_MIN_FREE);
-		else
-			dinfo->ring_space = (dinfo->ring.size +
-					     dinfo->ring_head)
-				- (dinfo->ring_tail + RING_MIN_FREE);
+		dinfo->ring_space = get_ring_space(dinfo);
+
 		if (dinfo->ring_head != last_head) {
 			end = jiffies + (HZ * 3);
 			last_head = dinfo->ring_head;
@@ -1513,12 +1526,7 @@ #endif
 
 	dinfo->ring_head = INREG(PRI_RING_HEAD) & RING_HEAD_MASK;
 	dinfo->ring_tail = INREG(PRI_RING_TAIL) & RING_TAIL_MASK;
-	if (dinfo->ring_tail + RING_MIN_FREE < dinfo->ring_head)
-		dinfo->ring_space = dinfo->ring_head
-			- (dinfo->ring_tail + RING_MIN_FREE);
-	else
-		dinfo->ring_space = (dinfo->ring.size + dinfo->ring_head)
-			- (dinfo->ring_tail + RING_MIN_FREE);
+	dinfo->ring_space = get_ring_space(dinfo);
 }
 
 static void
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