* UDMA 133 on a 40 pin cable
@ 2003-01-02 18:29 Teodor Iacob
2003-01-02 19:37 ` Alan Cox
0 siblings, 1 reply; 19+ messages in thread
From: Teodor Iacob @ 2003-01-02 18:29 UTC (permalink / raw)
To: linux-kernel
Hello,
Today i mounted a HDD on my secondary IDE on a 40 pin cable and surprise
the kernel set it up on UDMA 133:
hdd: 120103200 sectors (61493 MB) w/2048KiB Cache, CHS=119150/16/63, UDMA(133)
I wouldn't have notice this unless I got some errors:
Jan 2 20:20:40 theo kernel: hdd: dma_intr: status=0x51 { DriveReady SeekComplete Error }
Jan 2 20:20:40 theo kernel: hdd: dma_intr: error=0x84 { DriveStatusError BadCRC }
Jan 2 20:20:40 theo kernel: hdd: dma_intr: status=0x51 { DriveReady SeekComplete Error }
Jan 2 20:20:40 theo kernel: hdd: dma_intr: error=0x84 { DriveStatusError BadCRC }
Jan 2 20:20:40 theo kernel: hdd: dma_intr: status=0x51 { DriveReady SeekComplete Error }
Jan 2 20:20:40 theo kernel: hdd: dma_intr: error=0x84 { DriveStatusError BadCRC }
Jan 2 20:20:40 theo kernel: hdd: dma_intr: status=0x51 { DriveReady SeekComplete Error }
Jan 2 20:20:40 theo kernel: hdd: dma_intr: error=0x84 { DriveStatusError BadCRC }
Jan 2 20:20:40 theo kernel: ide1: reset: success
This box is running kernel: 2.4.18-18.8.0 ( redhat 8.0 )
Teo
^ permalink raw reply [flat|nested] 19+ messages in thread* Re: UDMA 133 on a 40 pin cable 2003-01-02 18:29 UDMA 133 on a 40 pin cable Teodor Iacob @ 2003-01-02 19:37 ` Alan Cox 2003-01-02 18:59 ` Teodor Iacob 2003-01-02 22:00 ` Lionel Bouton 0 siblings, 2 replies; 19+ messages in thread From: Alan Cox @ 2003-01-02 19:37 UTC (permalink / raw) To: Teodor Iacob; +Cc: Linux Kernel Mailing List On Thu, 2003-01-02 at 18:29, Teodor Iacob wrote: > Hello, > > Today i mounted a HDD on my secondary IDE on a 40 pin cable and surprise > the kernel set it up on UDMA 133: > > hdd: 120103200 sectors (61493 MB) w/2048KiB Cache, CHS=119150/16/63, UDMA(133) What controller and disks ? > I wouldn't have notice this unless I got some errors: It got CRC errors, not suprisingly and will drop back. Nevertheless it shouldnt have gotten this wrong, so more info would be good. ^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: UDMA 133 on a 40 pin cable 2003-01-02 19:37 ` Alan Cox @ 2003-01-02 18:59 ` Teodor Iacob 2003-01-02 19:21 ` Samuel Flory 2003-01-02 22:00 ` Lionel Bouton 1 sibling, 1 reply; 19+ messages in thread From: Teodor Iacob @ 2003-01-02 18:59 UTC (permalink / raw) To: Alan Cox; +Cc: Linux Kernel Mailing List On Thu, Jan 02, 2003 at 07:37:49PM +0000, Alan Cox wrote: > On Thu, 2003-01-02 at 18:29, Teodor Iacob wrote: > > Hello, > > > > Today i mounted a HDD on my secondary IDE on a 40 pin cable and surprise > > the kernel set it up on UDMA 133: > > > > hdd: 120103200 sectors (61493 MB) w/2048KiB Cache, CHS=119150/16/63, UDMA(133) > > What controller and disks ? Sorry I didn't append this info from the first time.. there it goes: 00:11.1 IDE interface: VIA Technologies, Inc. VT82C586B PIPC Bus Master IDE (rev 06) hdd: Maxtor 6Y060L0, ATA DISK drive the harddisk is DiamondPlus9 60GB 7200 rpm UDMA133 .. and the mainbboard is Soltek 75-FRV with KT400 chipset > > > I wouldn't have notice this unless I got some errors: > > It got CRC errors, not suprisingly and will drop back. Nevertheless it > shouldnt have gotten this wrong, so more info would be good. > > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- Teodor Iacob, Network Administrator Astral TELECOM Internet ^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: UDMA 133 on a 40 pin cable 2003-01-02 18:59 ` Teodor Iacob @ 2003-01-02 19:21 ` Samuel Flory 2003-01-02 19:23 ` Teodor Iacob 0 siblings, 1 reply; 19+ messages in thread From: Samuel Flory @ 2003-01-02 19:21 UTC (permalink / raw) To: Teodor Iacob; +Cc: Alan Cox, Linux Kernel Mailing List Teodor Iacob wrote: >On Thu, Jan 02, 2003 at 07:37:49PM +0000, Alan Cox wrote: > > >>On Thu, 2003-01-02 at 18:29, Teodor Iacob wrote: >> >> >>>Hello, >>> >>>Today i mounted a HDD on my secondary IDE on a 40 pin cable and surprise >>>the kernel set it up on UDMA 133: >>> >>>hdd: 120103200 sectors (61493 MB) w/2048KiB Cache, CHS=119150/16/63, UDMA(133) >>> >>> >>What controller and disks ? >> >> > >Sorry I didn't append this info from the first time.. there it goes: > >00:11.1 IDE interface: VIA Technologies, Inc. VT82C586B PIPC Bus Master IDE (rev 06) > >hdd: Maxtor 6Y060L0, ATA DISK drive > >the harddisk is DiamondPlus9 60GB 7200 rpm UDMA133 .. and the mainbboard is Soltek 75-FRV >with KT400 chipset > > What's hdc? Hdd is the secondary slave. If it's the only device on the chain you should make sure you jumper the drive as a master. -- There is no such thing as obsolete hardware. Merely hardware that other people don't want. (The Second Rule of Hardware Acquisition) Sam Flory <sflory@rackable.com> ^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: UDMA 133 on a 40 pin cable 2003-01-02 19:21 ` Samuel Flory @ 2003-01-02 19:23 ` Teodor Iacob 2003-01-02 19:47 ` Samuel Flory 0 siblings, 1 reply; 19+ messages in thread From: Teodor Iacob @ 2003-01-02 19:23 UTC (permalink / raw) To: Samuel Flory; +Cc: Alan Cox, Linux Kernel Mailing List > >00:11.1 IDE interface: VIA Technologies, Inc. VT82C586B PIPC Bus Master > >IDE (rev 06) > > > >hdd: Maxtor 6Y060L0, ATA DISK drive > > > >the harddisk is DiamondPlus9 60GB 7200 rpm UDMA133 .. and the mainbboard > >is Soltek 75-FRV > >with KT400 chipset > > > > > > What's hdc? Hdd is the secondary slave. If it's the only device on > the chain you should make sure you jumper the drive as a master. HDC it's a CD-RW .. it was not used at the time of the error ( i was doing mke2fs on hdd1 when I got those errors in dmesg ). > > > -- > There is no such thing as obsolete hardware. > Merely hardware that other people don't want. > (The Second Rule of Hardware Acquisition) > Sam Flory <sflory@rackable.com> > > -- Teodor Iacob, Network Administrator Astral TELECOM Internet ^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: UDMA 133 on a 40 pin cable 2003-01-02 19:23 ` Teodor Iacob @ 2003-01-02 19:47 ` Samuel Flory 2003-01-02 20:37 ` Teodor Iacob 2003-01-03 2:26 ` Joshua Stewart 0 siblings, 2 replies; 19+ messages in thread From: Samuel Flory @ 2003-01-02 19:47 UTC (permalink / raw) To: Teodor Iacob; +Cc: Alan Cox, Linux Kernel Mailing List Teodor Iacob wrote: >>>00:11.1 IDE interface: VIA Technologies, Inc. VT82C586B PIPC Bus Master >>>IDE (rev 06) >>> >>>hdd: Maxtor 6Y060L0, ATA DISK drive >>> >>>the harddisk is DiamondPlus9 60GB 7200 rpm UDMA133 .. and the mainbboard >>>is Soltek 75-FRV >>>with KT400 chipset >>> >>> >>> >>> >> What's hdc? Hdd is the secondary slave. If it's the only device on >>the chain you should make sure you jumper the drive as a master. >> >> > >HDC it's a CD-RW .. it was not used at the time of the error ( i was doing >mke2fs on hdd1 when I got those errors in dmesg ). > > > Try setting the cd-rw as a slave, and the hard drive as a master. -- There is no such thing as obsolete hardware. Merely hardware that other people don't want. (The Second Rule of Hardware Acquisition) Sam Flory <sflory@rackable.com> ^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: UDMA 133 on a 40 pin cable 2003-01-02 19:47 ` Samuel Flory @ 2003-01-02 20:37 ` Teodor Iacob 2003-01-03 2:26 ` Joshua Stewart 1 sibling, 0 replies; 19+ messages in thread From: Teodor Iacob @ 2003-01-02 20:37 UTC (permalink / raw) To: Samuel Flory; +Cc: Alan Cox, Linux Kernel Mailing List On Thu, Jan 02, 2003 at 11:47:56AM -0800, Samuel Flory wrote: > > Try setting the cd-rw as a slave, and the hard drive as a master. My problem was that it was recognised as UDMA 133 on a 40 pin cable... actually after those errors ( which repeats 4 times in the log ) the hard-drive works fine.. I just thought of it as a bug.. I shall not use the hard-drive in this configuration anyway... > > -- > There is no such thing as obsolete hardware. > Merely hardware that other people don't want. > (The Second Rule of Hardware Acquisition) > Sam Flory <sflory@rackable.com> > > > > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- Teodor Iacob, Network Administrator Astral TELECOM Internet ^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: UDMA 133 on a 40 pin cable 2003-01-02 19:47 ` Samuel Flory 2003-01-02 20:37 ` Teodor Iacob @ 2003-01-03 2:26 ` Joshua Stewart 1 sibling, 0 replies; 19+ messages in thread From: Joshua Stewart @ 2003-01-03 2:26 UTC (permalink / raw) To: Samuel Flory; +Cc: linux-kernel On Thu, 2003-01-02 at 14:47, Samuel Flory wrote: > Try setting the cd-rw as a slave, and the hard drive as a master. I tried setting up my CDRW as a slave and couldn't get it to work. Later I found documentation stating that my Memorex 48-24-48 CDRW was unable to function as a slave device. Let me know if you can get it to work. Josh ^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: UDMA 133 on a 40 pin cable 2003-01-02 19:37 ` Alan Cox 2003-01-02 18:59 ` Teodor Iacob @ 2003-01-02 22:00 ` Lionel Bouton 2003-01-02 22:40 ` Ross Biro ` (2 more replies) 1 sibling, 3 replies; 19+ messages in thread From: Lionel Bouton @ 2003-01-02 22:00 UTC (permalink / raw) To: Alan Cox, Andre Hedrick; +Cc: Teodor Iacob, Linux Kernel Mailing List Happy new year everybody Alan Cox wrote: >It got CRC errors, not suprisingly and will drop back. Nevertheless it >shouldnt have gotten this wrong, so more info would be good. > > I'm wondering some things about IDE 40/80 pin cables since some time ago : - somehow the circuitry can make the difference between 40 and 80 pin (probably some pins are shorted or not by the cables or some cable-type-dependent impedance between wires is mesured) and set a bit for us to use. - most probably the same circuitry can't verify the length of the cables or their overall quality but I'm unsure. #1 How is the 40/80 pin detection done at the hardware level ? #2 Are there any other cable-quality hardware tests done by the chipsets ? How ? I've encountered a barebone design (Mocha P4, uses 2.5" drives) where the IDE cable was 40-pin but : - has a single drive connector instead of the common two, - its length is only around 10 or 15 cm. A buyer contacted me for SiS IDE driver directions on this platform and confirmed this at least for his purchase. #3 Is the above cable electrically able to sustain 66+ UDMA transfers (could I hack a driver in order to bypass the 80pin cable detection and make it work properly) ? #4 Are the electrical specs for 66+ UDMA transfers public (couldn't find by googling) ? Where can we find them ? Here I mean some really basic specs (max Resistance/Capacity/Inductance between wires, max signal propagation delays and so on) and not general high level specs (material, connector design, length ranges allowed in the general 80-pin, 2 drives case). Any hints on these Andre ? LB. ^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: UDMA 133 on a 40 pin cable 2003-01-02 22:00 ` Lionel Bouton @ 2003-01-02 22:40 ` Ross Biro 2003-01-02 22:42 ` Teodor Iacob 2003-01-02 23:24 ` UDMA 133 on a 40 pin cable Alan Cox 2003-01-03 16:14 ` Vojtech Pavlik 2 siblings, 1 reply; 19+ messages in thread From: Ross Biro @ 2003-01-02 22:40 UTC (permalink / raw) To: Lionel Bouton Cc: Alan Cox, Andre Hedrick, Teodor Iacob, Linux Kernel Mailing List > > #1 How is the 40/80 pin detection done at the hardware level ? On the motherboard end of the 80 conductor cable, the connector shorts one of the pins to ground (maybe pin 38). The ide controller just checks to see if the pin is pulled low or not. Pulled low = 80 pin. That's one of the reasons it's important to plug IDE cables in the correct way. Ross ^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: UDMA 133 on a 40 pin cable 2003-01-02 22:40 ` Ross Biro @ 2003-01-02 22:42 ` Teodor Iacob 2003-01-03 1:04 ` Lionel Bouton 0 siblings, 1 reply; 19+ messages in thread From: Teodor Iacob @ 2003-01-02 22:42 UTC (permalink / raw) To: Ross Biro Cc: Lionel Bouton, Alan Cox, Andre Hedrick, Linux Kernel Mailing List Ok then after all .. what I see on my box could be a stupid IDE controller? On Thu, Jan 02, 2003 at 02:40:20PM -0800, Ross Biro wrote: > > > >#1 How is the 40/80 pin detection done at the hardware level ? > > > On the motherboard end of the 80 conductor cable, the connector shorts > one of the pins to ground (maybe pin 38). The ide controller just > checks to see if the pin is pulled low or not. Pulled low = 80 pin. > That's one of the reasons it's important to plug IDE cables in the > correct way. > > Ross > -- Teodor Iacob, Network Administrator Astral TELECOM Internet ^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: UDMA 133 on a 40 pin cable 2003-01-02 22:42 ` Teodor Iacob @ 2003-01-03 1:04 ` Lionel Bouton 2003-01-03 1:57 ` Alan Cox 0 siblings, 1 reply; 19+ messages in thread From: Lionel Bouton @ 2003-01-03 1:04 UTC (permalink / raw) To: Teodor Iacob; +Cc: Linux Kernel Mailing List Teodor Iacob wrote: >Ok then after all .. what I see on my box could be a stupid IDE controller? > > Chip bug, unknown chip revision with different register layout needing reverse engineering (or did VIA learn that providing specs enlarge their market share ?) or plain driver bug. I don't think ATA66+ controllers can be within spec if they don't detect 40 vs 80 pin cables. LB. ^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: UDMA 133 on a 40 pin cable 2003-01-03 1:04 ` Lionel Bouton @ 2003-01-03 1:57 ` Alan Cox 2003-01-03 10:20 ` IDE termination (was Re: UDMA 133 on a 40 pin cable) John Bradford 0 siblings, 1 reply; 19+ messages in thread From: Alan Cox @ 2003-01-03 1:57 UTC (permalink / raw) To: Lionel Bouton; +Cc: Teodor Iacob, Linux Kernel Mailing List On Fri, 2003-01-03 at 01:04, Lionel Bouton wrote: > I don't think ATA66+ controllers can be within spec if they don't detect > 40 vs 80 pin cables. I wish. Alas not in the real world. Alan ^ permalink raw reply [flat|nested] 19+ messages in thread
* IDE termination (was Re: UDMA 133 on a 40 pin cable) 2003-01-03 1:57 ` Alan Cox @ 2003-01-03 10:20 ` John Bradford 2003-01-03 10:29 ` Andre Hedrick 0 siblings, 1 reply; 19+ messages in thread From: John Bradford @ 2003-01-03 10:20 UTC (permalink / raw) To: Alan Cox; +Cc: Lionel.Bouton, Teodor.Iacob, linux-kernel > > I don't think ATA66+ controllers can be within spec if they don't detect > > 40 vs 80 pin cables. > > I wish. Alas not in the real world. Something that occurs to me, which is somewhat related to this: My understanding, (which might be wrong) is that termination of the IDE bus is partly handled by each connected devicem rather like modern floppy drives, (in contrast to SCSI, 10-base-2, old floppy drives etc, where the termination is handled by devices at the physical ends of the cable). So if you connnect a really old IDE disk, say a 20 Mb one, and an ATA-100 one to the same bus, is the termination then out of spec, (analogous to using passive terminators on anything other than a SCSI-1 bus), because presumably the termination requirements are stricter for the higher bus speed and signaling on both edges? Just wondered. John. ^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: IDE termination (was Re: UDMA 133 on a 40 pin cable) 2003-01-03 10:20 ` IDE termination (was Re: UDMA 133 on a 40 pin cable) John Bradford @ 2003-01-03 10:29 ` Andre Hedrick 0 siblings, 0 replies; 19+ messages in thread From: Andre Hedrick @ 2003-01-03 10:29 UTC (permalink / raw) To: John Bradford; +Cc: Alan Cox, Lionel.Bouton, Teodor.Iacob, linux-kernel On Fri, 3 Jan 2003, John Bradford wrote: > > > I don't think ATA66+ controllers can be within spec if they don't detect > > > 40 vs 80 pin cables. > > > > I wish. Alas not in the real world. > > Something that occurs to me, which is somewhat related to this: > > My understanding, (which might be wrong) is that termination of the > IDE bus is partly handled by each connected devicem rather like modern > floppy drives, (in contrast to SCSI, 10-base-2, old floppy drives etc, > where the termination is handled by devices at the physical ends of > the cable). > > So if you connnect a really old IDE disk, say a 20 Mb one, and an > ATA-100 one to the same bus, is the termination then out of spec, > (analogous to using passive terminators on anything other than a SCSI-1 > bus), because presumably the termination requirements are stricter for > the higher bus speed and signaling on both edges? All are self terminating, and are effected by the M:S:C jumpers for their responses. Things like leak current times and other events that are based on various decay rates against an assumed Z value for a given ribbon+devices+host combination will change things rudely. There are issues of shadow registers and pattern responses. But you got the swing of it! Cheers, Andre Hedrick LAD Storage Consulting Group ^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: UDMA 133 on a 40 pin cable 2003-01-02 22:00 ` Lionel Bouton 2003-01-02 22:40 ` Ross Biro @ 2003-01-02 23:24 ` Alan Cox 2003-01-02 22:45 ` Ross Biro 2003-01-03 1:15 ` Lionel Bouton 2003-01-03 16:14 ` Vojtech Pavlik 2 siblings, 2 replies; 19+ messages in thread From: Alan Cox @ 2003-01-02 23:24 UTC (permalink / raw) To: Lionel Bouton; +Cc: Andre Hedrick, Teodor Iacob, Linux Kernel Mailing List On Thu, 2003-01-02 at 22:00, Lionel Bouton wrote: > I'm wondering some things about IDE 40/80 pin cables since some time ago : > - somehow the circuitry can make the difference between 40 and 80 pin > (probably some pins are shorted or not by the cables or some > cable-type-dependent impedance between wires is mesured) and set a bit > for us to use. > - most probably the same circuitry can't verify the length of the cables > or their overall quality but I'm unsure. > > #1 How is the 40/80 pin detection done at the hardware level ? > #2 Are there any other cable-quality hardware tests done by the chipsets > ? How ? Oh god. Andre described this one as needing a "two beer" explanation. I'd recommend stronger drinks however. > I've encountered a barebone design (Mocha P4, uses 2.5" drives) where > the IDE cable was 40-pin but : > - has a single drive connector instead of the common two, > - its length is only around 10 or 15 cm. > A buyer contacted me for SiS IDE driver directions on this platform and > confirmed this at least for his purchase. > > #3 Is the above cable electrically able to sustain 66+ UDMA transfers > (could I hack a driver in order to bypass the 80pin cable detection and > make it work properly) ? It is possible to do this yes. Other vendors do it as well. Careful cable choice lets you meet the electrical requirements other ways in certain situations. ^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: UDMA 133 on a 40 pin cable 2003-01-02 23:24 ` UDMA 133 on a 40 pin cable Alan Cox @ 2003-01-02 22:45 ` Ross Biro 2003-01-03 1:15 ` Lionel Bouton 1 sibling, 0 replies; 19+ messages in thread From: Ross Biro @ 2003-01-02 22:45 UTC (permalink / raw) To: Alan Cox Cc: Lionel Bouton, Andre Hedrick, Teodor Iacob, Linux Kernel Mailing List > > >>#3 Is the above cable electrically able to sustain 66+ UDMA transfers >>(could I hack a driver in order to bypass the 80pin cable detection and >>make it work properly) ? >> >> > >It is possible to do this yes. Other vendors do it as well. Careful >cable choice lets you meet the electrical requirements other ways in >certain situations. > > > > on the kernel command line ide0=ATA66 bypasses the check for ide channel 0. Ross ^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: UDMA 133 on a 40 pin cable 2003-01-02 23:24 ` UDMA 133 on a 40 pin cable Alan Cox 2003-01-02 22:45 ` Ross Biro @ 2003-01-03 1:15 ` Lionel Bouton 1 sibling, 0 replies; 19+ messages in thread From: Lionel Bouton @ 2003-01-03 1:15 UTC (permalink / raw) To: Alan Cox; +Cc: Linux Kernel Mailing List Alan Cox wrote: >On Thu, 2003-01-02 at 22:00, Lionel Bouton wrote: > > >>#2 Are there any other cable-quality hardware tests done by the chipsets >>? How ? >> >> > >Oh god. Andre described this one as needing a "two beer" explanation. >I'd recommend stronger drinks however. > > In that case the thing should be within my body specifications :-) >>#3 Is the above cable electrically able to sustain 66+ UDMA transfers >>(could I hack a driver in order to bypass the 80pin cable detection and >>make it work properly) ? >> >> > >It is possible to do this yes. Other vendors do it as well. Careful >cable choice lets you meet the electrical requirements other ways in >certain situations. > > Given what I see on sales (various out of spec drives/cables and maybe even controllers) I'm suspecting that some of these vendors might use plain trial and error cable testing... This is why I'd prefer to have real electrical specs at hand to make my own checks. LB. ^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: UDMA 133 on a 40 pin cable 2003-01-02 22:00 ` Lionel Bouton 2003-01-02 22:40 ` Ross Biro 2003-01-02 23:24 ` UDMA 133 on a 40 pin cable Alan Cox @ 2003-01-03 16:14 ` Vojtech Pavlik 2 siblings, 0 replies; 19+ messages in thread From: Vojtech Pavlik @ 2003-01-03 16:14 UTC (permalink / raw) To: Lionel Bouton Cc: Alan Cox, Andre Hedrick, Teodor Iacob, Linux Kernel Mailing List On Thu, Jan 02, 2003 at 11:00:56PM +0100, Lionel Bouton wrote: > Happy new year everybody > > > Alan Cox wrote: > > >It got CRC errors, not suprisingly and will drop back. Nevertheless it > >shouldnt have gotten this wrong, so more info would be good. > > > > > > I'm wondering some things about IDE 40/80 pin cables since some time ago : > - somehow the circuitry can make the difference between 40 and 80 pin > (probably some pins are shorted or not by the cables or some > cable-type-dependent impedance between wires is mesured) and set a bit > for us to use. Yes. There are two types of this circuitry: 1) Just-a-capacitor-on-mainboard. When the pin in question (CBLID) is connected to ground via a capacitor on the mainboard, the attached devices can detect the cable and the IDE driver can ask them. 2) GPIO pin on mainboard. One of the chipset's GPIO pins gets wired to CBLID and then the chipset can see what cable is installed. Unfortunately, the wiring is mainboard (not chipset) dependent, and thus only the BIOS can know. Anyway, mixing various types of devices and mainboards there are always cases where you get incorrect results. For some reason the ATA people couldn't get this ever right. The second method is safer, and mostly works for chipsets where there is a 'cable detect scratch register', where the BIOS writes the 80/40 pin cable information. Modern chipsets (Intel, AMD) implement this. VIA doesn't. There is no way for a driver to read the cable type on a VIA mainboard - it can ask the drives (but they can lie if they're mixed with older devices, and if there is no cap on the mainboard), and it can guess from the settings the BIOS used to program the UDMA speeds. Currently it does the later, because it works in 99% of cases - the BIOS will only set the chipset to UDMA66+ if it sees the cable on the right GPIO pins. > - most probably the same circuitry can't verify the length of the cables > or their overall quality but I'm unsure. It can not. Very modern drives and chipsets can adapt the termination and various aspects of signalling, but cannot measure whether the cable is suitable for a certain speed or not. The only way to really know is to try to do a transfer. Or two. Or a thousand. > #1 How is the 40/80 pin detection done at the hardware level ? See above. Also see the ATA specs, it's there. > #2 Are there any other cable-quality hardware tests done by the chipsets > ? How ? Not really. > I've encountered a barebone design (Mocha P4, uses 2.5" drives) where > the IDE cable was 40-pin but : > - has a single drive connector instead of the common two, > - its length is only around 10 or 15 cm. > A buyer contacted me for SiS IDE driver directions on this platform and > confirmed this at least for his purchase. > > #3 Is the above cable electrically able to sustain 66+ UDMA transfers > (could I hack a driver in order to bypass the 80pin cable detection and > make it work properly) ? If you use ide0=ata66, the cable should be forced to 80pin. Also, it can work if the cable is short and there is only one drive. Make sure it's not bent too much, too. > #4 Are the electrical specs for 66+ UDMA transfers public (couldn't find > by googling) ? Where can we find them ? > Here I mean some really basic specs (max Resistance/Capacity/Inductance > between wires, max signal propagation delays and so on) and not general > high level specs (material, connector design, length ranges allowed in > the general 80-pin, 2 drives case). Mostly. See the ATA spec. > Any hints on these Andre ? -- Vojtech Pavlik SuSE Labs ^ permalink raw reply [flat|nested] 19+ messages in thread
end of thread, other threads:[~2003-01-03 16:06 UTC | newest] Thread overview: 19+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2003-01-02 18:29 UDMA 133 on a 40 pin cable Teodor Iacob 2003-01-02 19:37 ` Alan Cox 2003-01-02 18:59 ` Teodor Iacob 2003-01-02 19:21 ` Samuel Flory 2003-01-02 19:23 ` Teodor Iacob 2003-01-02 19:47 ` Samuel Flory 2003-01-02 20:37 ` Teodor Iacob 2003-01-03 2:26 ` Joshua Stewart 2003-01-02 22:00 ` Lionel Bouton 2003-01-02 22:40 ` Ross Biro 2003-01-02 22:42 ` Teodor Iacob 2003-01-03 1:04 ` Lionel Bouton 2003-01-03 1:57 ` Alan Cox 2003-01-03 10:20 ` IDE termination (was Re: UDMA 133 on a 40 pin cable) John Bradford 2003-01-03 10:29 ` Andre Hedrick 2003-01-02 23:24 ` UDMA 133 on a 40 pin cable Alan Cox 2003-01-02 22:45 ` Ross Biro 2003-01-03 1:15 ` Lionel Bouton 2003-01-03 16:14 ` Vojtech Pavlik
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