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

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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 <hkallweit1@gmail.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Tested-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
This commit is contained in:
Heiner Kallweit 2021-12-04 21:04:40 +01:00 committed by Wolfram Sang
parent 8c7a89678f
commit 4f7275fc7e
1 changed files with 5 additions and 11 deletions
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16
drivers/i2c/busses/i2c-i801.c
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@ -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);