On May 29 2016 or thereabouts, Corey Minyard wrote:
> From: Corey Minyard <cminy...@mvista.com>
>
> Since hwpec is only used for block transactions, move it out of
> i801_access() and into i801_block_transaction().
>
> Signed-off-by: Corey Minyard <cminy...@mvista.com>
> ---
> drivers/i2c/busses/i2c-i801.c | 47
> +++++++++++++++++++++++--------------------
> 1 file changed, 25 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
> index 205f9d0..222be9c 100644
> --- a/drivers/i2c/busses/i2c-i801.c
> +++ b/drivers/i2c/busses/i2c-i801.c
> @@ -656,11 +656,22 @@ static int i801_set_block_buffer_mode(struct i801_priv
> *priv)
> }
>
> /* Block transaction function */
> -static int i801_block_transaction(struct i801_priv *priv,
> +static int i801_block_transaction(struct i801_priv *priv, unsigned short
> flags,
> union i2c_smbus_data *data, char read_write,
> - int command, int hwpec)
> + int command)
> {
> int result = 0;
> + int hwpec = (priv->features & FEATURE_SMBUS_PEC)
> + && (flags & I2C_CLIENT_PEC)
> + && command != I2C_SMBUS_QUICK
> + && command != I2C_SMBUS_I2C_BLOCK_DATA;
> +
> + if (hwpec) /* enable/disable hardware PEC */
> + outb_p(inb_p(SMBAUXCTL(priv)) | SMBAUXCTL_CRC,
> + SMBAUXCTL(priv));
> + else
> + outb_p(inb_p(SMBAUXCTL(priv)) & (~SMBAUXCTL_CRC),
> + SMBAUXCTL(priv));
>
> if (read_write == I2C_SMBUS_WRITE
> || command == I2C_SMBUS_I2C_BLOCK_DATA) {
> @@ -685,6 +696,16 @@ static int i801_block_transaction(struct i801_priv *priv,
> read_write,
> command);
>
> + /*
> + * Some BIOSes don't like it when PEC is enabled at reboot or
> + * resume time, so we forcibly disable it after every
> + * transaction. Turn off E32B for the same reason.
> + */
> + if (hwpec)
If I read correctly, there should not be a need for the if, but do the
outb_p() call unconditionally. In i801_access, this is guarded by
(hwpec || block), and we are in the block case anyway.
So now, with this testm you won't disable SMBAUXCTL_E32B after every
transaction, which causes problems according to the comment above.
Cheers,
Benjamin
> + outb_p(inb_p(SMBAUXCTL(priv)) &
> + ~(SMBAUXCTL_CRC | SMBAUXCTL_E32B),
> + SMBAUXCTL(priv));
> +
> return result;
> }
>
> @@ -693,7 +714,6 @@ static s32 i801_access(struct i2c_adapter *adap, u16 addr,
> unsigned short flags, char read_write, u8 command,
> int size, union i2c_smbus_data *data)
> {
> - int hwpec;
> int block = 0;
> int ret = 0, xact = 0;
> int hostc = -1;
> @@ -701,10 +721,6 @@ static s32 i801_access(struct i2c_adapter *adap, u16
> addr,
>
> pm_runtime_get_sync(&priv->pci_dev->dev);
>
> - hwpec = (priv->features & FEATURE_SMBUS_PEC) && (flags & I2C_CLIENT_PEC)
> - && size != I2C_SMBUS_QUICK
> - && size != I2C_SMBUS_I2C_BLOCK_DATA;
> -
> switch (size) {
> case I2C_SMBUS_QUICK:
> outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
> @@ -773,25 +789,12 @@ static s32 i801_access(struct i2c_adapter *adap, u16
> addr,
> goto out;
> }
>
> - if (hwpec) /* enable/disable hardware PEC */
> - outb_p(inb_p(SMBAUXCTL(priv)) | SMBAUXCTL_CRC, SMBAUXCTL(priv));
> - else
> - outb_p(inb_p(SMBAUXCTL(priv)) & (~SMBAUXCTL_CRC),
> - SMBAUXCTL(priv));
> -
> if (block)
> - ret = i801_block_transaction(priv, data, read_write, size,
> - hwpec);
> + ret = i801_block_transaction(priv, flags, data, read_write,
> + size);
> else
> ret = i801_transaction(priv, xact);
>
> - /* Some BIOSes don't like it when PEC is enabled at reboot or resume
> - time, so we forcibly disable it after every transaction. Turn off
> - E32B for the same reason. */
> - if (hwpec || block)
> - outb_p(inb_p(SMBAUXCTL(priv)) &
> - ~(SMBAUXCTL_CRC | SMBAUXCTL_E32B), SMBAUXCTL(priv));
> -
> if (hostc >= 0)
> pci_write_config_byte(priv->pci_dev, SMBHSTCFG, hostc);
>
