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f0a6d77b35
The packed transfer mode masks and also the {pio|mwdma|udma}_mask fields
of *struct*s ata_device and ata_port_info are declared as *unsigned long*
(which is a 64-bit type on 64-bit architectures) but actually the packed
masks occupy only 20 bits (7 PIO modes, 5 MWDMA modes, and 8 UDMA modes)
and the PIO/MWDMA/UDMA masks easily fit into just 8 bits each, so we can
safely use (always 32-bit) *unsigned int* variables instead. This saves
745 bytes of object code in libata-core.o alone, not to mention LLDDs...
Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
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 Restructured Text 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.