Michael Brown 19d3e966d9 [pcnet32] Eliminate redundant register read ...

The value of ( ( x & 0x0c00 ) | 0x0c00 ) is always 0x0c00 regardless
of the value of x, and so the read_csr() is redundant.  (There are no
read side effects for this register, according to the datasheet.)

This line of code originated in Linux kernel 2.3.19pre1 as

  a->write_csr(ioaddr, 80, a->read_csr(ioaddr, 80) | 0x0c00);

and was modified in kernel 2.3.41pre4 to read

  a->write_csr(ioaddr, 80, (a->read_csr(ioaddr, 80) & 0x0C00) | 0x0c00);

In the absence of commit messages, the intention of the code is
unclear.  However, the logic resulting in a fixed value of 0x0c00 has
remained unaltered for over 17 years, and can probably be assumed to
have the correct overall result.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

2017-03-23 17:43:13 +02:00

..

bitbash

[legal] Relicense files under GPL2_OR_LATER_OR_UBDL

2015-03-02 14:17:31 +00:00

block

[scsi] Avoid duplicate calls to scsicmd_close()

2017-03-09 13:07:57 +00:00

bus

[usb] Use correct length for memcpy()

2017-03-22 14:14:57 +02:00

infiniband

[golan] Bug fixes and improved paging allocation method

2017-03-23 16:03:40 +02:00

linux

[af_packet] Add new AF_PACKET driver for Linux

2017-01-22 14:02:54 +00:00

net

[pcnet32] Eliminate redundant register read

2017-03-23 17:43:13 +02:00

nvs

[legal] Relicense files under GPL2_OR_LATER_OR_UBDL

2015-03-02 14:17:31 +00:00

usb

[xhci] Avoid accessing beyond end of endpoint context array

2017-03-21 16:22:42 +02:00