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

JIRA: https://issues.redhat.com/browse/RHEL-113184

commit 3a3c6b7
Author: Heiner Kallweit <hkallweit1@gmail.com>
Date:   Fri Feb 21 21:30:46 2025 +0100

    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

Signed-off-by: Steve Best <sbest@redhat.com>

Author: sfbest

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;
 	}