linux-stable.git/drivers/thunderbolt/eeprom.c, branch linux-rolling-lts

thunderbolt: Update eeprom.c function documentation

2025-09-17T05:32:59+00:00

Make eeprom.c function documentation compliant with current kernel-doc
standards. No functional changes.

Signed-off-by: Alan Borzeszkowski 
Signed-off-by: Mika Westerberg

lib/crc32: standardize on crc32c() name for Castagnoli CRC32

2025-02-09T04:06:30+00:00

For historical reasons, the Castagnoli CRC32 is available under 3 names:
crc32c(), crc32c_le(), and __crc32c_le().  Most callers use crc32c().
The more verbose versions are not really warranted; there is no "_be"
version that the "_le" version needs to be differentiated from, and the
leading underscores are pointless.

Therefore, let's standardize on just crc32c().  Remove the other two
names, and update callers accordingly.

Specifically, the new crc32c() comes from what was previously
__crc32c_le(), so compared to the old crc32c() it now takes a size_t
length rather than unsigned int, and it's now in linux/crc32.h instead
of just linux/crc32c.h (which includes linux/crc32.h).

Later patches will also rename __crc32c_le_combine(), crc32c_le_base(),
and crc32c_le_arch().

Reviewed-by: Ard Biesheuvel 
Link: https://lore.kernel.org/r/20250208024911.14936-5-ebiggers@kernel.org
Signed-off-by: Eric Biggers

thunderbolt: Expose router DROM through debugfs

2025-01-05T08:35:03+00:00

Router DROM contains information that might be usable for development
and debugging purposes. For example when new entries are added to the
USB4 spec it is useful to be able to look for them without need to
change the kernel.

For this reason expose the DROM through debugfs.

Signed-off-by: Mika Westerberg

thunderbolt: Ignore data CRC mismatch for USB4 routers

2023-06-16T06:53:27+00:00

This is also something not always updated after the DROM contents itself
so issue warning but continue parsing it as we do for pre-USB4 DROMs
too.

Signed-off-by: Mika Westerberg

thunderbolt: Refactor DROM reading

2023-03-14T14:15:45+00:00

The NVM reading code has a series of gotos that potentially introduce
unexpected behaviors with retries if something unexpected has failed
to parse.

Refactor the code to remove the gotos and drop the retry logic.

Signed-off-by: Mario Limonciello 
[mw: renamed root switch to host router, split device handling too]
Signed-off-by: Mika Westerberg

thunderbolt: use `tb_eeprom_get_drom_offset` to discover DROM offset

2023-03-14T13:54:49+00:00

The static function `tb_eeprom_get_drom_offset` has more safety guards
for the DROM offset fetching.  Use this instead of just `tb_sw_read`

No intended functional changes.

Signed-off-by: Mario Limonciello 
Signed-off-by: Mika Westerberg

thunderbolt: Rename EEPROM handling bits to match USB4 spec

2022-03-04T14:10:36+00:00

The structure `tb_eeprom_ctl` is used to show the bits accessed when
reading/writing EEPROM.

As this structure is specified in the USB4 spec as `VSC_CS_4` update
the names and use of members to match the specification. This should not
change anything functionally.

Signed-off-by: Mario Limonciello 
Signed-off-by: Mika Westerberg

thunderbolt: Retry DROM reads for more failure scenarios

2022-03-04T14:10:36+00:00

Currently DROM reads are only retried in the case that parsing failed.
However if the size or CRC fails, then there should also be a retry.

This helps with reading the DROM on TBT3 devices connected to AMD
Yellow Carp which will sometimes fail on the first attempt.

Signed-off-by: Mario Limonciello 
Signed-off-by: Mika Westerberg

thunderbolt: Fix DROM handling for USB4 DROM

2021-06-15T10:51:07+00:00

DROM for USB4 host/device has a shorter header than Thunderbolt DROM
header. This patch addresses host/device with USB4 DROM (According to spec:
Universal Serial Bus 4 (USB4) Device ROM Specification, Rev 1.0, Feb-2021).

While there correct the data_len field to be 12 bits and rename
__unknown1 to reserved following the spec.

Signed-off-by: Gil Fine 
Signed-off-by: Mika Westerberg

thunderbolt: Add support for USB4 DROM

2021-03-18T15:25:32+00:00

USB4 router DROM differs sligthly from Thunderbolt 1-3 DROM. For
instance it does not include UID and CRC8 in the header section, and it
has product descriptor genereric entry to describe the product IDs and
related information. If the "Version" field in the DROM header section
reads 3 it means the router only has USB4 DROM and if it reads 1 it
means the router supports TBT3 compatible DROM.

For this reason, update the DROM parsing code to support "pure" USB4
DROMs too.

While there drop the extra empty line at the end of tb_drom_read().

Signed-off-by: Mika Westerberg