Commit 4f7275fc authored by Heiner Kallweit's avatar Heiner Kallweit Committed by Wolfram Sang
Browse files

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: default avatarHeiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: default avatarJean Delvare <jdelvare@suse.de>
Tested-by: default avatarJean Delvare <jdelvare@suse.de>
Signed-off-by: default avatarWolfram Sang <wsa@kernel.org>
parent 8c7a8967

drivers/i2c/busses/i2c-i801.c

+5 −11
Original line number Diff line number Diff line
@@ -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);