i2c: i801: Improve too small kill wait time in i801_check_post

In my tests terminating a transaction took about 25ms, what is
in line with the chip-internal timeout as described in 5.21.3.2
"Bus Time Out" in [0]. Therefore the 2ms delay is too low.
Instead of a fixed delay let's use i801_wait_intr() here,
this also facilitates the status handling.

This potential issue seems to have been existing forever, but as no
related problem is known, treat it as an improvement.

[0] Intel document #326776-003, 7 Series PCH datasheet

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/ad4ef645-5d03-4833-a0b6-f31f8fd06483@gmail.com

diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index 9097bb9cdb9e849cb64df66e71a1361c6dd4049f..6a4147054b4974fbcc3092c5f671b6a16e695b37 100644 (file)
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -441,12 +441,11 @@ static int i801_check_post(struct i801_priv *priv, int status)
        if (unlikely(status < 0)) {
                /* try to stop the current command */
                outb_p(SMBHSTCNT_KILL, SMBHSTCNT(priv));
-               usleep_range(1000, 2000);
+               status = i801_wait_intr(priv);
                outb_p(0, SMBHSTCNT(priv));
 
                /* Check if it worked */
-               status = inb_p(SMBHSTSTS(priv));
-               if ((status & SMBHSTSTS_HOST_BUSY) || !(status & SMBHSTSTS_FAILED))
+               if (status < 0 || !(status & SMBHSTSTS_FAILED))
                        pci_dbg(priv->pci_dev, "Failed terminating the transaction\n");
                return -ETIMEDOUT;
        }