Re: [PATCH v2 07/10] i2c: i801: centralize configuring non-block commands in i801_simple_transaction

[Jean Delvare <jdelvare@suse.de>]

Hi Heiner,

On Mon, 19 Dec 2022 19:20:55 +0100, Heiner Kallweit wrote:
> Currently configuring command register settings is disributed over multiple
> functions. At first cetralize this for non-block commands in

Typo: cetralize -> centralize.

> i801_simple_transaction().
> 
> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
> ---
>  drivers/i2c/busses/i2c-i801.c | 31 ++++++++++++++-----------------
>  1 file changed, 14 insertions(+), 17 deletions(-)

I'm happy with the idea (well I kind of suggested it in the first
place, so...), and pleased to see that the diffstats confirm it was a
good idea.

> diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
> index d7182f7c8..0d49e9587 100644
> --- a/drivers/i2c/busses/i2c-i801.c
> +++ b/drivers/i2c/busses/i2c-i801.c
> @@ -738,35 +738,47 @@ static void i801_set_hstadd(struct i801_priv *priv, u8 addr, char read_write)
>  
>  /* Single value transaction function */
>  static int i801_simple_transaction(struct i801_priv *priv, union i2c_smbus_data *data,
> -				   char read_write, int command)
> +				   u8 addr, u8 hstcmd, char read_write, int command)

See my review of patch 5 about how I don't like some of the parameter
names. But I realize now that this problem predates your patches,
functions i801_block_transaction_by_block() and
i801_block_transaction_byte_by_byte() already carry the confusion. So
I'm fine leaving it as is for now, maybe we can clean it up later
driver-wide.

>  {
>  	int xact, ret;
>  
>  	switch (command) {
>  	case I2C_SMBUS_QUICK:
> +		i801_set_hstadd(priv, addr, read_write);
>  		xact = I801_QUICK;
>  		break;
>  	case I2C_SMBUS_BYTE:
> +		i801_set_hstadd(priv, addr, read_write);
> +		if (read_write == I2C_SMBUS_WRITE)
> +			outb_p(hstcmd, SMBHSTCMD(priv));
>  		xact = I801_BYTE;
>  		break;
>  	case I2C_SMBUS_BYTE_DATA:
> +		i801_set_hstadd(priv, addr, read_write);
>  		if (read_write == I2C_SMBUS_WRITE)
>  			outb_p(data->byte, SMBHSTDAT0(priv));
> +		outb_p(hstcmd, SMBHSTCMD(priv));
>  		xact = I801_BYTE_DATA;
>  		break;
>  	case I2C_SMBUS_WORD_DATA:
> +		i801_set_hstadd(priv, addr, read_write);
>  		if (read_write == I2C_SMBUS_WRITE) {
>  			outb_p(data->word & 0xff, SMBHSTDAT0(priv));
>  			outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1(priv));
>  		}
> +		outb_p(hstcmd, SMBHSTCMD(priv));
>  		xact = I801_WORD_DATA;
>  		break;
>  	case I2C_SMBUS_PROC_CALL:
> +		i801_set_hstadd(priv, addr, I2C_SMBUS_WRITE);
>  		outb_p(data->word & 0xff, SMBHSTDAT0(priv));
>  		outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1(priv));
> +		outb_p(hstcmd, SMBHSTCMD(priv));
> +		read_write = I2C_SMBUS_READ;
>  		xact = I801_PROC_CALL;
>  		break;
>  	default:
> +		pci_err(priv->pci_dev, "Unsupported transaction %d\n", command);
>  		return -EOPNOTSUPP;
>  	}

The split between patches 7 and 8 isn't really clean, as you have dead
code here at this step, which will only become active with the next
patch. I'm willing to let it go though.

>  
> @@ -857,25 +869,10 @@ static s32 i801_access(struct i2c_adapter *adap, u16 addr,
>  
>  	switch (size) {
>  	case I2C_SMBUS_QUICK:
> -		i801_set_hstadd(priv, addr, read_write);
> -		break;
>  	case I2C_SMBUS_BYTE:
> -		i801_set_hstadd(priv, addr, read_write);
> -		if (read_write == I2C_SMBUS_WRITE)
> -			outb_p(command, SMBHSTCMD(priv));
> -		break;
>  	case I2C_SMBUS_BYTE_DATA:
> -		i801_set_hstadd(priv, addr, read_write);
> -		outb_p(command, SMBHSTCMD(priv));
> -		break;
>  	case I2C_SMBUS_WORD_DATA:
> -		i801_set_hstadd(priv, addr, read_write);
> -		outb_p(command, SMBHSTCMD(priv));
> -		break;
>  	case I2C_SMBUS_PROC_CALL:
> -		i801_set_hstadd(priv, addr, I2C_SMBUS_WRITE);
> -		outb_p(command, SMBHSTCMD(priv));
> -		read_write = I2C_SMBUS_READ;
>  		break;
>  	case I2C_SMBUS_BLOCK_DATA:
>  		i801_set_hstadd(priv, addr, read_write);
> @@ -922,7 +919,7 @@ static s32 i801_access(struct i2c_adapter *adap, u16 addr,
>  	if (block)
>  		ret = i801_block_transaction(priv, data, read_write, size);
>  	else
> -		ret = i801_simple_transaction(priv, data, read_write, size);
> +		ret = i801_simple_transaction(priv, data, addr, command, read_write, size);
>  
>  	/* Some BIOSes don't like it when PEC is enabled at reboot or resume
>  	 * time, so we forcibly disable it after every transaction.

Reviewed-by: Jean Delvare <jdelvare@suse.de>

-- 
Jean Delvare
SUSE L3 Support