Re: [PATCH v2] platform/x86: intel_cht_int33fe: Work around BIOS bug on some devices

[Hans de Goede]

Hi,

On 04-09-17 14:23, Andy Shevchenko wrote:
> On Sat, 2017-09-02 at 18:20 +0200, Hans de Goede wrote:
> > At least one BIOS enumerates the max17047 both through the INT33FE
> > ACPI
> > device (it is right there in the resources table) as well as through a
> > separate MAX17047 device.
> >
> > This commit checks for the max17047 already being enumerated through
> > a separate MAX17047 ACPI device and if so it uses the i2c-client
> > instantiated for this and attaches the device-props for the max17047
> > to
> > that i2c-client.
>
> This one looks acceptable wrt buggy BIOS workaround, few comments below
> (I can do it when applying)

The suggested comments are fine with me, feel free to fix
those up while applying.

Thanks & Regards,

Hans



> > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> > ---
> > Changes in v2:
> > -Check acpi_companion HID instead of dev_name
> > ---
> >   drivers/platform/x86/intel_cht_int33fe.c | 71
> > +++++++++++++++++++++++++++-----
> >   1 file changed, 61 insertions(+), 10 deletions(-)
> >
> > diff --git a/drivers/platform/x86/intel_cht_int33fe.c
> > b/drivers/platform/x86/intel_cht_int33fe.c
> > index da706e2c4232..a9cbc4b8ca63 100644
> > --- a/drivers/platform/x86/intel_cht_int33fe.c
> > +++ b/drivers/platform/x86/intel_cht_int33fe.c
> > @@ -34,6 +34,42 @@ struct cht_int33fe_data {
> >   	struct i2c_client *pi3usb30532;
> >   };
> >   
> > +/*
> > + * Grrr I severly dislike buggy BIOS-es. At least one BIOS enumerates
> > + * the max17047 both through the INT33FE ACPI device (it is right
> > there
> > + * in the resources table) as well as through a separate MAX17047
> > device.
> > + *
> > + * These helpers are used to work around this by checking if an i2c-
> > client
> > + * for the max17047 has already been registered.
> > + */
> > +int cht_int33fe_check_for_max17047(struct device *dev, void *data)
> > +{
> > +	struct acpi_device *companion = ACPI_COMPANION(dev);
> > +	struct i2c_client **max17047 = data;
> > +	const char *hid;
> > +
>
> I would assign companion right here.
> > +	if (!companion)
> > +		return 0;
> > +
> > +	hid = acpi_device_hid(companion);
> > +
> > +	/* The MAX17047 ACPI node doesn't have an UID, so we don't
> > check that */
>
> > +	if (strcmp(hid, "MAX17047") == 0) {
>
> if (strcmp())
>   return 0;
>
> ?
>
> > +		*max17047 = to_i2c_client(dev);
> > +		return 1;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +struct i2c_client *cht_int33fe_find_max17047(void)
> > +{
> > +	struct i2c_client *max17047 = NULL;
> > +
> > +	i2c_for_each_dev(&max17047, cht_int33fe_check_for_max17047);
> > +	return max17047;
> > +}
> > +
> >   static const char * const max17047_suppliers[] = { "bq24190-charger"
> > };
> >   
> >   static const struct property_entry max17047_props[] = {
> > @@ -46,9 +82,10 @@ static int cht_int33fe_probe(struct i2c_client
> > *client)
> >   	struct device *dev = &client->dev;
> >   	struct i2c_board_info board_info;
> >   	struct cht_int33fe_data *data;
> > +	struct i2c_client *max17047;
> >   	unsigned long long ptyp;
> >   	acpi_status status;
> > -	int fusb302_irq;
> > +	int ret, fusb302_irq;
> >   
> >   	status = acpi_evaluate_integer(ACPI_HANDLE(dev), "PTYP",
> > NULL, &ptyp);
> >   	if (ACPI_FAILURE(status)) {
> > @@ -75,13 +112,25 @@ static int cht_int33fe_probe(struct i2c_client
> > *client)
> >   	if (!data)
> >   		return -ENOMEM;
> >   
> > -	memset(&board_info, 0, sizeof(board_info));
> > -	strlcpy(board_info.type, "max17047", I2C_NAME_SIZE);
> > -	board_info.properties = max17047_props;
> > -
> > -	data->max17047 = i2c_acpi_new_device(dev, 1, &board_info);
> > -	if (!data->max17047)
> > -		return -EPROBE_DEFER; /* Wait for the i2c-adapter to
> > load */
> > +	/* Work around BIOS bug, see comment on
> > cht_int33fe_find_max17047 */
> > +	max17047 = cht_int33fe_find_max17047();
> > +	if (max17047) {
> > +		/* Pre-existing i2c-client for the max17047, add
> > device-props */
> > +		ret = device_add_properties(&max17047->dev,
> > max17047_props);
> > +		if (ret)
> > +			return ret;
> > +		/* And re-probe to get the new device-props applied.
> > */
> > +		ret = device_reprobe(&max17047->dev);
> > +		if (ret)
> > +			dev_warn(dev, "Reprobing max17047 error:
> > %d\n", ret);
> > +	} else {
> > +		memset(&board_info, 0, sizeof(board_info));
> > +		strlcpy(board_info.type, "max17047", I2C_NAME_SIZE);
> > +		board_info.properties = max17047_props;
> > +		data->max17047 = i2c_acpi_new_device(dev, 1,
> > &board_info);
> > +		if (!data->max17047)
> > +			return -EPROBE_DEFER; /* Wait for i2c-adapter
> > to load */
> > +	}
> >   
> >   	memset(&board_info, 0, sizeof(board_info));
> >   	strlcpy(board_info.type, "fusb302", I2C_NAME_SIZE);
> > @@ -106,7 +155,8 @@ static int cht_int33fe_probe(struct i2c_client
> > *client)
> >   	i2c_unregister_device(data->fusb302);
> >   
> >   out_unregister_max17047:
> > -	i2c_unregister_device(data->max17047);
> > +	if (data->max17047)
> > +		i2c_unregister_device(data->max17047);
> >   
> >   	return -EPROBE_DEFER; /* Wait for the i2c-adapter to load */
> >   }
> > @@ -117,7 +167,8 @@ static int cht_int33fe_remove(struct i2c_client
> > *i2c)
> >   
> >   	i2c_unregister_device(data->pi3usb30532);
> >   	i2c_unregister_device(data->fusb302);
> > -	i2c_unregister_device(data->max17047);
> > +	if (data->max17047)
> > +		i2c_unregister_device(data->max17047);
> >   
> >   	return 0;
> >   }