Commit fc9d53af authored by Manu Abraham's avatar Manu Abraham Committed by Linus Torvalds
Browse files

[PATCH] bttv: fix dst i2c read/write timeout failure.



Attached is a patch to bttv which fixes the following problems.

Affected cards and problems:
~~~~~~~~~~~~~~~~~~~~~~~~
o VP-1020 (200103A) Tuning problems, device detection.
o VP-1020 (DST-MOT) Errors during tuning, device detection fails in a while.
o VP-1030 (DST-CI) Tuning sometimes fails after CI commands.
o VP-2031 (DCT-CI) Tuning problems

The timeout happens before the actual timeout occured in the MCU
on the board, and hence the problems.

Changes: (bttv-i2c.diff)
~~~~~~~~~~~~~~~~~~~~~~~~
o Changed the custom wait queue to wait_event_interruptible_timeout()
      - Suggestion by Johannes Stezenbach.

o Fixed the wait queue timeout problem
      - This fixes the timeout problem on various cards.
      - This problem was visible as many
          * Cannot tune to channels, when signal levels are very low.
          * app_info does not work in some conditions for CI based cards
      - Smaller values worked good for newer cards, but the older cards
suffered, settled down to the worst case values that could happen in any
eventuality.
Signed-off-by: default avatarManu Abraham <manu@kromtek.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 2ef41634
......@@ -29,6 +29,7 @@
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/jiffies.h>
#include <asm/io.h>
#include "bttvp.h"
......@@ -130,17 +131,14 @@ static u32 functionality(struct i2c_adapter *adap)
static int
bttv_i2c_wait_done(struct bttv *btv)
{
DECLARE_WAITQUEUE(wait, current);
int rc = 0;
add_wait_queue(&btv->i2c_queue, &wait);
if (0 == btv->i2c_done)
msleep_interruptible(20);
remove_wait_queue(&btv->i2c_queue, &wait);
/* timeout */
if (wait_event_interruptible_timeout(btv->i2c_queue,
btv->i2c_done, msecs_to_jiffies(85)) == -ERESTARTSYS)
rc = -EIO;
if (0 == btv->i2c_done)
/* timeout */
rc = -EIO;
if (btv->i2c_done & BT848_INT_RACK)
rc = 1;
btv->i2c_done = 0;
......
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