[PATCH] i2c: i801: Don't clear status flags twice in interrupt mode

From: Heiner Kallweit <hkallweit1@gmail.com>
To: Jean Delvare <jdelvare@suse.com>
Cc: "linux-i2c@vger.kernel.org" <linux-i2c@vger.kernel.org>
Subject: [PATCH] i2c: i801: Don't clear status flags twice in interrupt mode
Date: Thu, 2 Dec 2021 10:57:43 +0100	[thread overview]
Message-ID: <8fba896a-81c4-dda7-6481-92ae8dccf41c@gmail.com> (raw)

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@gmail.com>
---
 drivers/i2c/busses/i2c-i801.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index 7446bed78..82553e0cb 100644
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -438,9 +438,6 @@ 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;
 }
 
@@ -455,8 +452,10 @@ 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;
-- 
2.33.1

