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

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Message-ID: <c07a4ab0-e204-2f75-eb01-5bc4015372f1@redhat.com>
Date:   Thu, 31 Aug 2017 17:04:58 +0200
From:   Hans de Goede <hdegoede@...hat.com>
To:     Darren Hart <dvhart@...radead.org>,
        Andy Shevchenko <andy@...radead.org>
Cc:     platform-driver-x86@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] platform/x86: intel_cht_int33fe: Work around BIOS bug on
 some devices

Hi,

On 14-08-17 22:14, 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.
> 
> Signed-off-by: Hans de Goede <hdegoede@...hat.com>

What is the status of this patch ? It would be nice to get this fix
into 4.14.

Regards,

Hans


> ---
>   drivers/platform/x86/intel_cht_int33fe.c | 64 +++++++++++++++++++++++++++-----
>   1 file changed, 54 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/platform/x86/intel_cht_int33fe.c b/drivers/platform/x86/intel_cht_int33fe.c
> index da706e2c4232..5f1924fb3190 100644
> --- a/drivers/platform/x86/intel_cht_int33fe.c
> +++ b/drivers/platform/x86/intel_cht_int33fe.c
> @@ -34,6 +34,35 @@ 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)
> +{
> +	const char *name = dev_name(dev);
> +	struct i2c_client **max17047 = data;
> +
> +	if (name && strcmp(name, "i2c-MAX17047:00") == 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 +75,10 @@ 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 +105,25 @@ 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 +148,8 @@ 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 +160,8 @@ 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;
>   }
>