Fix UDMA throughput bug: tCYC averages t2CYCTYP/2, but the code
previously assumed it was the same as t2CYCTYP. (That is, it was
using just one clock edge, not both.) Move the table's type
declaration so it's adjacent to the table, making it more clear
what those numbers mean.
On one system this change increased throughput by almost 4x: UDMA/66
sometimes topped 23 MB/sec (on a drive known to do much better). On
another system it was around a 10% win (UDMA/66 up to 7+ MB/sec).
The difference might be caused by the ratio between memory and IDE
clocks. In the system with large speedup, this was exactly 2 (as a
workaround for a rev 1.1 silicon bug). The other system used a more
standard ratio of 1.63 (and rev 2.1 silicon) ... clock domain synch
might have some issues, they're not unheard-of.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
[bart: minor CodingStyle fixup per Sergei's suggestion]
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
CC drivers/ide/palm_bk3710.o
drivers/ide/palm_bk3710.c: In function 'palm_bk3710_probe':
drivers/ide/palm_bk3710.c:382: warning: assignment makes integer from pointer without a cast
Someone should fix hw_regs_t to neither be a typedef, nor
use "unsigned long" where it should use "void __iomem *".
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Replace setting of 'hwif->dma_ops' in the 'alim15x3' and 'palm_bk3710' drivers'
init_dma() methods with initializing the corresponding member of their 'struct
ide_port_info' instances and remove such setting from the 'hpt366' driver that
just doesn't use 'sff_dma_ops'. Along with some code save, this prepares us for
the next patch...
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
