Re: [PATCH] i2c: i801: Fix incorrect and needless software PEC disabling

[Heiner Kallweit <hkallweit1@gmail.com>]

On 26.10.2021 16:39, Jarkko Nikula wrote:
> Commit a6b8bb6a813a ("i2c: i801: Fix handling SMBHSTCNT_PEC_EN")
> attempts to disable software PEC by clearing the SMBHSTCNT_PEC_EN (bit 7)
> in the SMBus Host Control register (I/O SMBHSTCNT) but incorrectly
> clears it in the PCI Host Configuration register (PCI SMBHSTCFG).
> 
Indeed, my bad. Mixed up HSTCFG and HSTCNT here.

> This clearing is actually needless since after above commit the
> SMBHSTCNT_PEC_EN is never set and the register is initialized with known
> values.
> 
> Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
> ---
> I didn't add Fixes tag and Cc stable@vger.kernel.org since I don't see
> this causes any real issues. A few platforms I checked the PCI Host
> Configuration register bit 7 was reserved 0.
> ---
>  drivers/i2c/busses/i2c-i801.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
> index 115660dce722..b6048a571543 100644
> --- a/drivers/i2c/busses/i2c-i801.c
> +++ b/drivers/i2c/busses/i2c-i801.c
> @@ -1657,7 +1657,6 @@ static void i801_setup_hstcfg(struct i801_priv *priv)
>  	unsigned char hstcfg = priv->original_hstcfg;
>  
>  	hstcfg &= ~SMBHSTCFG_I2C_EN;	/* SMBus timing */
> -	hstcfg &= ~SMBHSTCNT_PEC_EN;	/* Disable software PEC */
>  	hstcfg |= SMBHSTCFG_HST_EN;
>  	pci_write_config_byte(priv->pci_dev, SMBHSTCFG, hstcfg);
>  }
>