Re:Re: SiI3112 DMA

[juan . carlos]

Will we see a patch for 2.4.22-23 too? (Nudge nudge wink wink)

If this information is of any use for you, I was playing with a SiI 3112
yesterday (Abit mobo, Athlon XP2500 1800 MHz, Seagate 120MB 7200 RPM SATA
drive) and noticed that, while with 2.4.22-ac4 I had a hdparm -t result of
16 MB/sec, with 2.4.23-pre6 I got 25 MB/sec -- which is still less than the
32-33 MB/sec I get with normal ATA. Does that make any sense?

> It is an issue with first generation FIS transfer on the wire.
>
> Take the size of the request in sectors and divide by 15 or 7.5K.
Standard FIS packet size is 8K.
>
> Without going into much detail because of NDA's, there needs to be a
special DMA engine build table.
>
> I did it once then lost the code because of lack of sleep.

Juan Carlos Castro y Castro
VIVO - Diretoria de Processos de Negócio - Projetos
Tel.: 55 (21) 2574-3506 - Cel.: 55 (21) 9603-7440
juan.carlos@xxxxxxxxxxx
jcastro@xxxxxxxxxxxxxx





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