On Monday, 2. July 2007, Thorsten Leemhuis wrote: > > but Alan Cox wrote: > > http://www.mail-archive.com/linux-ide%40vger.kernel.org/msg07417.html > >> Its ich_pata_133 - all the newer chips are. > > Intel afaik never supported Ultra ATA 133 officially in any of the > mainstream desktop or mobile chipsets. You're probably right! But, what about Intel's ICH5 and ICH7/7-R (i945, i975)? see ata_piix.c: line 193ff { 0x8086, 0x24DB, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich_pata_133 }, [...] { 0x8086, 0x27DF, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich_pata_133 }, On the other hand, we can leave it, because of a "off-by-one error" in ata_piix.c, do_pata_set_dmamode, line ~770: (the comment is important!) /* * --> UDMA is handled by a combination of clock switching and * selection of dividers <--- * [...] */ u_speed = min(2 - (udma & 1), udma); if (udma == 5) u_clock = 0x1000; /* 100Mhz */ <-- wrong! it's 133Mhz. else if (udma > 2) u_clock = 1; /* 66Mhz */ else u_clock = 0; /* 33Mhz */ => for udma = 6(133MB/s) , we get u_speed=2 and u_clock=1 for udma = 4(66MB/s), we get the "same" values! (u_speed=2 and u_clock=1) ... so, atleast for ata_piix, UDMA6 and UDMA4 *is* the same, right? > > >> They work even better if you > >> set them into AHCI mode in the BIOS and then they should "just work" with > >> recent kernels as the AHCI driver now matches by class. > > And "Gaston, Jason D" <jason.d.gaston@xxxxxxxxx> didn't complain about it. > > it's a "bit" confusing with all "native" AHCI SATA chipset that have to emulate > > PATA for compatibility reasons... > > Well, just FYI: on my Laptop AHCI is enabled and used for the SATA hard > disk. But the DVD drive still is a pata one afaics (I'm not in front of > the machine, so I can't check), connected via the pata controller -- so > for me there is no emulation involved (at least afaics). > I know. I wanted to say something else... but it doesn't really matter (not every operating system supports AHCI-only controllers by default...) Thanks, Chr. - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
