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| author | Heiner Kallweit <hkallweit1@gmail.com> | 2021-12-04 21:04:40 +0100 |
|---|---|---|
| committer | Wolfram Sang <wsa@kernel.org> | 2021-12-09 15:52:10 +0100 |
| commit | 4f7275fc7e570dfc46f733ff8ae131cb128a4758 (patch) | |
| tree | 14d52b34d6e1d92cc49c71af2b1a5e55d7b7dd4f /drivers/i2c | |
| parent | i2c: i801: Don't read back cleared status in i801_check_pre() (diff) | |
| download | linux-4f7275fc7e570dfc46f733ff8ae131cb128a4758.tar.xz linux-4f7275fc7e570dfc46f733ff8ae131cb128a4758.zip | |
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 <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>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-i801.c | 16 |
1 files changed, 5 insertions, 11 deletions
diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c index b452f36c9c73..7428cc6af5cc 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); |