Commit 1bb1ff3e7c74 ("i2c: octeon: Improve performance if interrupt is
early") modified octeon_i2c_wait() & octeon_i2c_hlc_wait() to attempt to
check for a valid bit being clear & if not to sleep for a while then try
again before waiting on a waitqueue which may time out. However it does
so by sleeping within a function called as the condition provided to
wait_event_timeout() which seems to cause strange behaviour, with the
system hanging during boot with the condition being checked constantly &
the timeout not seeming to have any effect.
Fix this by instead checking for the valid bit being clear in the
octeon_i2c(_hlc)_wait() functions & sleeping there if that condition is
not met, then calling the wait_event_timeout with a condition that does
not sleep.
Tested on a Rhino Labs UTM-8 with Octeon CN7130.
Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>
Cc: David Daney <david.daney@xxxxxxxxxx>
Cc: Jan Glauber <jglauber@xxxxxxxxxx>
Cc: Peter Swain <pswain@xxxxxxxxxx>
Cc: Wolfram Sang <wsa@xxxxxxxxxxxxx>
Cc: linux-i2c@xxxxxxxxxxxxxxx
---
drivers/i2c/busses/i2c-octeon-core.c | 58 ++++++++++--------------------------
1 file changed, 15 insertions(+), 43 deletions(-)
diff --git a/drivers/i2c/busses/i2c-octeon-core.c b/drivers/i2c/busses/i2c-octeon-core.c
index 419b54b..2e270a1 100644
--- a/drivers/i2c/busses/i2c-octeon-core.c
+++ b/drivers/i2c/busses/i2c-octeon-core.c
@@ -36,24 +36,6 @@ static bool octeon_i2c_test_iflg(struct octeon_i2c *i2c)
return (octeon_i2c_ctl_read(i2c) & TWSI_CTL_IFLG);
}
-static bool octeon_i2c_test_ready(struct octeon_i2c *i2c, bool *first)
-{
- if (octeon_i2c_test_iflg(i2c))
- return true;
-
- if (*first) {
- *first = false;
- return false;
- }
-
- /*
- * IRQ has signaled an event but IFLG hasn't changed.
- * Sleep and retry once.
- */
- usleep_range(I2C_OCTEON_EVENT_WAIT, 2 * I2C_OCTEON_EVENT_WAIT);
- return octeon_i2c_test_iflg(i2c);
-}
-
/**
* octeon_i2c_wait - wait for the IFLG to be set
* @i2c: The struct octeon_i2c
@@ -80,8 +62,13 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c)
}
i2c->int_enable(i2c);
- time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_ready(i2c, &first),
- i2c->adap.timeout);
+ time_left = i2c->adap.timeout;
+ if (!octeon_i2c_test_iflg(i2c)) {
+ usleep_range(I2C_OCTEON_EVENT_WAIT, 2 * I2C_OCTEON_EVENT_WAIT);
+ time_left = wait_event_timeout(i2c->queue,
+ octeon_i2c_test_iflg(i2c),
+ time_left);
+ }
i2c->int_disable(i2c);
if (i2c->broken_irq_check && !time_left &&
@@ -99,26 +86,8 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c)
static bool octeon_i2c_hlc_test_valid(struct octeon_i2c *i2c)
{
- return (__raw_readq(i2c->twsi_base + SW_TWSI(i2c)) & SW_TWSI_V) == 0;
-}
-
-static bool octeon_i2c_hlc_test_ready(struct octeon_i2c *i2c, bool *first)
-{
/* check if valid bit is cleared */
- if (octeon_i2c_hlc_test_valid(i2c))
- return true;
-
- if (*first) {
- *first = false;
- return false;
- }
-
- /*
- * IRQ has signaled an event but valid bit isn't cleared.
- * Sleep and retry once.
- */
- usleep_range(I2C_OCTEON_EVENT_WAIT, 2 * I2C_OCTEON_EVENT_WAIT);
- return octeon_i2c_hlc_test_valid(i2c);
+ return (__raw_readq(i2c->twsi_base + SW_TWSI(i2c)) & SW_TWSI_V) == 0;
}
static void octeon_i2c_hlc_int_clear(struct octeon_i2c *i2c)
@@ -176,7 +145,6 @@ static void octeon_i2c_hlc_disable(struct octeon_i2c *i2c)
*/
static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
{
- bool first = true;
int time_left;
/*
@@ -194,9 +162,13 @@ static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
}
i2c->hlc_int_enable(i2c);
- time_left = wait_event_timeout(i2c->queue,
- octeon_i2c_hlc_test_ready(i2c, &first),
- i2c->adap.timeout);
+ time_left = i2c->adap.timeout;
+ if (!octeon_i2c_hlc_test_valid(i2c)) {
+ usleep_range(I2C_OCTEON_EVENT_WAIT, 2 * I2C_OCTEON_EVENT_WAIT);
+ time_left = wait_event_timeout(i2c->queue,
+ octeon_i2c_hlc_test_valid(i2c),
+ time_left);
+ }
i2c->hlc_int_disable(i2c);
if (!time_left)
octeon_i2c_hlc_int_clear(i2c);
--
2.10.2
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