Messages in this thread | | | From | Manish Lachwani <> | Subject | RE: Disk Performance Issues [AMD Viper plus IDE chipset problems. (wrong udma "autodetection")] | Date | Tue, 19 Nov 2002 18:10:46 -0800 |
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I have noticed something with the IDE drivers especially with the Seagate drives. The promise driver (eg 20277) detects the UDMA 5 mode correctly.
This is what it does:
byte ultra_66 = ((id->dma_ultra & 0x0010) || (id->dma_ultra & 0x0008)) ? 1 : 0; byte ultra_100 = ((id->dma_ultra & 0x0020) || (ultra_66)) ? 1 : 0; byte ultra_133 = ((id->dma_ultra & 0x0040) || (ultra_100)) ? 1 : 0;
Now, lets take a PIIX driver
int ultra100 = ((dev->device == PCI_DEVICE_ID_INTEL_82801BA_8) || (dev->device == PCI_DEVICE_ID_INTEL_82801BA_9) || (dev->device == PCI_DEVICE_ID_INTEL_82801CA_10)) ? 1 : 0; int ultra66 = ((ultra100) || (dev->device == PCI_DEVICE_ID_INTEL_82801AA_1) || (dev->device == PCI_DEVICE_ID_INTEL_82372FB_1)) ? 1 : 0;
if ((id->dma_ultra & 0x0020) && (udma_66) && (ultra100)) { speed = XFER_UDMA_5;
where ultra100 and ultra66 is not or'ed with 0x0010 and 0x0008. The final check is only with 0x0020. I have found this issues with other IDE drivers like amd74xx.c, serverworks.c etc. SO, make the above changes in the drivers and u should see UDMA 5 on those seagate drives on startup ...
Thanks Manish
-----Original Message----- From: Alan Cox [mailto:alan@lxorguk.ukuu.org.uk] Sent: Saturday, November 16, 2002 3:34 PM To: Miguel S Filipe Cc: Linux Kernel Mailing List Subject: Re: Disk Performance Issues [AMD Viper plus IDE chipset problems. (wrong udma "autodetection")]
On Sat, 2002-11-16 at 20:19, Miguel S Filipe wrote: > Hello there, > > I'm sending this email about a problem with udma settings > in a TigerMP motherboard, wich supports UDMA 100. > I've send it to my distribution mailing list, and several others, to no > avail, so, has a last resort I send it now to the Linux ML. > I'm using pure vanilla linux-2.4.19, and I tried all possible configs > settings that I though that could affect this problem.
If I remember rightly 2.4.19 doesnt have full support for the AMD 760MP/X although - 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/ - 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/
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