libata-sff: avoid byte swapping in ata_sff_data_xfer()
commit2102d7497393e982bf38ffe8f5fd3d487104880d
authorSergei Shtylyov <sshtylyov@ru.mvista.com>
Sun, 15 Feb 2009 19:30:38 +0000 (15 23:30 +0400)
committerJeff Garzik <jgarzik@redhat.com>
Wed, 10 Jun 2009 11:50:16 +0000 (10 07:50 -0400)
tree9693052c22db544384d433e95052d50779377c4a
parent4da646b7b52552f3b43eae27ffa5aa2c200f6db6
libata-sff: avoid byte swapping in ata_sff_data_xfer()

Handling of the trailing byte in ata_sff_data_xfer() is suboptimal bacause:

- it always initializes the padding buffer to 0 which is not really needed in
  both the read and write cases;

- it has to use memcpy() to transfer a single byte from/to the padding buffer;

- it uses io{read|write}16() accessors which swap bytes on the big endian CPUs
  and so have to additionally convert the data from/to the little endian format
  instead of using io{read|write}16_rep() accessors which are not supposed to
  change the byte ordering.

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
drivers/ata/libata-sff.c