diff options
| author | Orczykowski, Juergen <juergen.orczykowski@siemens.com> | 2007-05-08 00:37:25 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-08 11:15:26 -0700 |
| commit | 71c6efd9930bd87249d007120425341d1293303d (patch) | |
| tree | 43cdb8c00526f16ca5e2cbb99012277fbb1fe116 /drivers/video/intelfb/intelfbhw.c | |
| parent | 33a9f640a2511155517d316e696654b84dd48654 (diff) | |
intelfb: fix ring space calculation
If there is less than 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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/video/intelfb/intelfbhw.c')
| -rw-r--r-- | 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 c1eb18bf088..16bc8d75e36 100644 --- a/drivers/video/intelfb/intelfbhw.c +++ b/drivers/video/intelfb/intelfbhw.c @@ -1428,6 +1428,24 @@ static void refresh_ring(struct intelfb_info *dinfo); 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 @@ wait_ring(struct intelfb_info *dinfo, int n) 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 @@ refresh_ring(struct intelfb_info *dinfo) 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 |