diff options
| author | Lukas Wunner <lukas@wunner.de> | 2020-12-31 06:10:32 +0100 |
|---|---|---|
| committer | Ard Biesheuvel <ardb@kernel.org> | 2020-12-31 10:28:53 +0100 |
| commit | 355845b738e76445c8522802552146d96cb4afa7 (patch) | |
| tree | 1302d389198bb98710ddef8c02b3baf9e8993a95 | |
| parent | 5c8fe583cce542aa0b84adc939ce85293de36e5e (diff) | |
efi/apple-properties: Reinstate support for boolean properties
Since commit 4466bf82821b ("efi/apple-properties: use
PROPERTY_ENTRY_U8_ARRAY_LEN"), my MacBook Pro issues a -ENODATA error
when trying to assign EFI properties to the discrete GPU:
pci 0000:01:00.0: assigning 56 device properties
pci 0000:01:00.0: error -61 assigning properties
That's because some of the properties have no value. They're booleans
whose presence can be checked by drivers, e.g. "use-backlight-blanking".
Commit 6e98503dba64 ("efi/apple-properties: Remove redundant attribute
initialization from unmarshal_key_value_pairs()") employed a trick to
store such booleans as u8 arrays (which is the data type used for all
other EFI properties on Macs): It cleared the property_entry's
"is_array" flag, thereby denoting that the value is stored inline in the
property_entry.
Commit 4466bf82821b erroneously removed that trick. It was probably a
little fragile to begin with.
Reinstate support for boolean properties by explicitly invoking the
PROPERTY_ENTRY_BOOL() initializer for properties with zero-length value.
Fixes: 4466bf82821b ("efi/apple-properties: use PROPERTY_ENTRY_U8_ARRAY_LEN")
Cc: <stable@vger.kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/be958bda75331a011d53c696d1deec8dccd06fd2.1609388549.git.lukas@wunner.de
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
| -rw-r--r-- | drivers/firmware/efi/apple-properties.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/drivers/firmware/efi/apple-properties.c b/drivers/firmware/efi/apple-properties.c index 34f53d898acb..e1926483ae2f 100644 --- a/drivers/firmware/efi/apple-properties.c +++ b/drivers/firmware/efi/apple-properties.c @@ -3,8 +3,9 @@ * apple-properties.c - EFI device properties on Macs * Copyright (C) 2016 Lukas Wunner <lukas@wunner.de> * - * Note, all properties are considered as u8 arrays. - * To get a value of any of them the caller must use device_property_read_u8_array(). + * Properties are stored either as: + * u8 arrays which can be retrieved with device_property_read_u8_array() or + * booleans which can be queried with device_property_present(). */ #define pr_fmt(fmt) "apple-properties: " fmt @@ -88,8 +89,12 @@ static void __init unmarshal_key_value_pairs(struct dev_header *dev_header, entry_data = ptr + key_len + sizeof(val_len); entry_len = val_len - sizeof(val_len); - entry[i] = PROPERTY_ENTRY_U8_ARRAY_LEN(key, entry_data, - entry_len); + if (entry_len) + entry[i] = PROPERTY_ENTRY_U8_ARRAY_LEN(key, entry_data, + entry_len); + else + entry[i] = PROPERTY_ENTRY_BOOL(key); + if (dump_properties) { dev_info(dev, "property: %s\n", key); print_hex_dump(KERN_INFO, pr_fmt(), DUMP_PREFIX_OFFSET, |