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

[Hans de Goede]

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 <hdego...@redhat.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;

  }