Re: [PATCH] i2c: i801: Fix SMBus ENXIO on resume from suspend.

[Alban Browaeys <alban.browaeys@gmail.com>]

My apologies.

This fix is a partial one: it only fixes the issue once
we unload then reload i2c-i801 .
This as when we load a second time  orig_hstcfg is set to the value the
first module load leftover.
Thus I will investigate the initial orig_hstcfg at boot to further the
fix.
I bet this only a few missing bits like HST_EN.

Best regards
Alban


Le mercredi 15 novembre 2017 à 18:01 +0100, Alban Browaeys a écrit :
> Disabling I2C_EN on resume as it was restored in
> suspend when we set pci config to its original value.
> 
> ENXIO landing in rmi_smb_get_version,  i2c-i802 debug
> pointing at i801_check_post and guesswork from reading
> probe which has this tweak.
> 
> i801_smbus 0000:00:1f.3: No response
> rmi4_smbus 0-002c: failed to get SMBus version number!
> i801_smbus 0000:00:1f.3: No response
> rmi4_physical rmi4-00: rmi_driver_reset_handler: Failed to read
> current IRQ mask.
> i801_smbus 0000:00:1f.3: No response
> rmi4_f01 rmi4-00.fn01: Failed to restore normal operation: -6.
> rmi4_f01 rmi4-00.fn01: Resume failed with code -6.
> rmi4_physical rmi4-00: Failed to suspend functions: -6
> rmi4_smbus 0-002c: Failed to resume device: -6
> rmi4_f03 rmi4-00.fn03: rmi_f03_pt_write: Failed to write to F03 TX
> register (-6).
> i801_smbus 0000:00:1f.3: No response
> rmi4_f03 rmi4-00.fn03: rmi_f03_pt_write: Failed to write to F03 TX
> register (-6).
> 
> Signed-off-by: Alban Browaeys <alban.browaeys@gmail.com>
> ---
>  drivers/i2c/busses/i2c-i801.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-
> i801.c
> index 9e12a53ef7b8..b7b6c8ee2176 100644
> --- a/drivers/i2c/busses/i2c-i801.c
> +++ b/drivers/i2c/busses/i2c-i801.c
> @@ -1707,9 +1707,14 @@ static int i801_suspend(struct device *dev)
>  
>  static int i801_resume(struct device *dev)
>  {
> +	unsigned char temp;
>  	struct pci_dev *pci_dev = to_pci_dev(dev);
>  	struct i801_priv *priv = pci_get_drvdata(pci_dev);
>  
> +	pci_read_config_byte(pci_dev, SMBHSTCFG, &temp);
> +	temp &= ~SMBHSTCFG_I2C_EN;	/* SMBus timing */
> +	pci_write_config_byte(pci_dev, SMBHSTCFG, temp);
> +
>  	i801_enable_host_notify(&priv->adapter);
>  
>  	return 0;