[PATCH RESEND 2/9] intelfb: Fix ring space calculation
From: "Antonino A. Daplas" <adaplas@gmail.com>
Date: 2007-02-25 10:26:58
Subsystem:
framebuffer layer, the rest · Maintainers:
Helge Deller, Linus Torvalds
From: Orczykowski, Juergen <redacted> 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: Dave Airlie <airlied@gmail.com> 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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