From 4f7275fc7e570dfc46f733ff8ae131cb128a4758 Mon Sep 17 00:00:00 2001 From: Heiner Kallweit Date: Sat, 4 Dec 2021 21:04:40 +0100 Subject: i2c: i801: Don't clear status flags twice in interrupt mode 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 handle polling mode by using the SMBus unlocking write to also clear the status flags if still set. To be precise: One could still argue that the status flags are cleared twice in interrupt mode, but it comes for free. Signed-off-by: Heiner Kallweit Reviewed-by: Jean Delvare Tested-by: Jean Delvare Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-i801.c | 16 +++++----------- 1 file changed, 5 insertions(+), 11 deletions(-) (limited to 'drivers/i2c/busses/i2c-i801.c') diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c index b452f36c9c7350..7428cc6af5cc00 100644 --- a/drivers/i2c/busses/i2c-i801.c +++ b/drivers/i2c/busses/i2c-i801.c @@ -356,11 +356,6 @@ 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; @@ -385,7 +380,6 @@ static int i801_check_post(struct i801_priv *priv, int status) !(status & SMBHSTSTS_FAILED)) dev_err(&priv->pci_dev->dev, "Failed terminating the transaction\n"); - outb_p(STATUS_FLAGS, SMBHSTSTS(priv)); return -ETIMEDOUT; } @@ -424,9 +418,6 @@ 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; } @@ -923,8 +914,11 @@ static s32 i801_access(struct i2c_adapter *adap, u16 addr, } out: - /* Unlock the SMBus device for use by BIOS/ACPI */ - outb_p(SMBHSTSTS_INUSE_STS, SMBHSTSTS(priv)); + /* + * Unlock the SMBus device for use by BIOS/ACPI, + * and clear status flags if not done already. + */ + outb_p(SMBHSTSTS_INUSE_STS | STATUS_FLAGS, SMBHSTSTS(priv)); pm_runtime_mark_last_busy(&priv->pci_dev->dev); pm_runtime_put_autosuspend(&priv->pci_dev->dev); -- cgit 1.2.3-korg