In interrupt mode we clear the status flags twice, in the interrupt
handler and in i801_check_post(). Remove clearing the status flags
from i801_check_post() and let i801_wait_intr() clear them in
polling mode. Another benefit is that now only checks for error
conditions are left in i801_check_post(), thus better matching the
function name.
Note: There's a comment in i801_check_post() that i801_wait_intr()
clears the error status bits. Actually this hasn't been true until
this change.
Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
---
v2:
- clear status flags also in i801_wait_byte_done()
- remove outdated comment at i801_check_post()
---
drivers/i2c/busses/i2c-i801.c | 21 ++++++++++-----------
1 file changed, 10 insertions(+), 11 deletions(-)
diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index 930c6edbe..60fdb2fec 100644
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -372,11 +372,6 @@ static int i801_check_pre(struct i801_priv *priv)
return 0;
}
-/*
- * Convert the status register to an error code, and clear it.
- * Note that status only contains the bits we want to clear, not the
- * actual register value.
- */
static int i801_check_post(struct i801_priv *priv, int status)
{
int result = 0;
@@ -440,9 +435,6 @@ static int i801_check_post(struct i801_priv *priv, int status)
dev_dbg(&priv->pci_dev->dev, "Lost arbitration\n");
}
- /* Clear status flags except BYTE_DONE, to be cleared by caller */
- outb_p(status, SMBHSTSTS(priv));
-
return result;
}
@@ -457,8 +449,10 @@ static int i801_wait_intr(struct i801_priv *priv)
status = inb_p(SMBHSTSTS(priv));
busy = status & SMBHSTSTS_HOST_BUSY;
status &= STATUS_ERROR_FLAGS | SMBHSTSTS_INTR;
- if (!busy && status)
+ if (!busy && status) {
+ outb_p(status, SMBHSTSTS(priv));
return status;
+ }
} while (time_is_after_eq_jiffies(timeout));
return -ETIMEDOUT;
@@ -473,8 +467,13 @@ static int i801_wait_byte_done(struct i801_priv *priv)
do {
usleep_range(250, 500);
status = inb_p(SMBHSTSTS(priv));
- if (status & (STATUS_ERROR_FLAGS | SMBHSTSTS_BYTE_DONE))
- return status & STATUS_ERROR_FLAGS;
+ status &= STATUS_ERROR_FLAGS | SMBHSTSTS_BYTE_DONE;
+ if (status & STATUS_ERROR_FLAGS) {
+ outb_p(status, SMBHSTSTS(priv));
+ return status;
+ } else if (status & SMBHSTSTS_BYTE_DONE) {
+ return 0;
+ }
} while (time_is_after_eq_jiffies(timeout));
return -ETIMEDOUT;
--
2.34.1
