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Simon Horman
e7e5ae7183
As it's name suggests, parse_eeprom() parses EEPROM data.
This is done by reading data, 16 bits at a time as follows:
for (i = 0; i < 128; i++)
((__le16 *) sromdata)[i] = cpu_to_le16(read_eeprom(np, i));
sromdata is at the same memory location as psrom.
And the type of psrom is a pointer to struct t_SROM.
As can be seen in the loop above, data is stored in sromdata, and thus psrom,
as 16-bit little-endian values.
However, the integer fields of t_SROM are host byte order integers.
And in the case of led_mode this leads to a little endian value
being incorrectly treated as host byte order.
Looking at rio_set_led_mode, this does appear to be a bug as that code
masks led_mode with 0x1, 0x2 and 0x8. Logic that would be effected by a
reversed byte order.
This problem would only manifest on big endian hosts.
Found by inspection while investigating a sparse warning
regarding the crc field of t_SROM.
I believe that warning is a false positive. And although I plan
to send a follow-up to use little-endian types for other the integer
fields of PSROM_t I do not believe that will involve any bug fixes.
Compile tested only.
Fixes: c3f45d322c ("dl2k: Add support for IP1000A-based cards")
Signed-off-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250425-dlink-led-mode-v1-1-6bae3c36e736@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.