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Description of problem:
It seems as though the kernel released by Red Hat for its Advance Server line of
products does not support the vt8233a chipset. This issue has been resolved
within the main Red Hat Linux kernels for 7.x,8.0 and 9 (in part as a result of
the bugzilla report #71545). 

Would it be possible for Red Hat to add in support for this newer hardware into
the Red Hat Enterprise kernels ? This will give the benefit of being able to use
the RHN system for maintaining our servers rather than running a custom kernel. 

We need this support added so that our customers will be able to use the full
UDMA6 (133MB/s), otherwise restricted to PIO4 (16MB/s). This is a considerable
performance loss for hardware capable of much more. 

I have created and tested a patch which will fix this and that applies cleanly
to the current 2.4.9-e.25 kernel source which I will attach to this report. 

Currently when trying to turn on UDMA you receive the following error:

hdparm -d 1 /dev/hda
 
/dev/hda:
 setting using_dma to 1 (on)
 HDIO_SET_DMA failed: Operation not permitted
 using_dma    =  0 (off)

and within dmesg it shows that this chipset it unknown to the 2.4.9-e.25 kernel:

VP_IDE: chipset revision 6
VP_IDE: not 100% native mode: will probe irqs later
VP_IDE: Unknown VIA SouthBridge, contact Vojtech Pavlik <vojtech>

Booting the same system to a custom kernel with my patch applied I am now able
to enable udma using hdparm:

# hdparm -d 1 /dev/hda

/dev/hda:
 setting using_dma to 1 (on)
 using_dma    =  1 (on)

and dmesg shows support for the chipset:

VP_IDE: chipset revision 6
VP_IDE: not 100% native mode: will probe irqs later
ide: Assuming 33MHz PCI bus speed for PIO modes; override with idebus=xx
VP_IDE: VIA vt8233a (rev 00) IDE UDMA133 controller on pci00:11.1

Please note that I used the 2.4.20 kernel from kernel.org as the basis for
creating the patch file for the ide-timing.h and via82cxxx.c files. This driver
version of 3.35 is not the newest available, you may wish to consider using
newer versions (as you did within the 2.4.20-18.7 kernel)

Please let me know if you have any follow-up questions and any time frame on
when this can be added into the Red Hat Enterprise 2.1 AS & ES kernels. 

Regards,
Clifford
Rackspace Managed Hosting.

Version-Release number of selected component (if applicable):
kernel-2.4.9-e.25

How reproducible:
Always

Steps to Reproduce:
1. Install a server/computer with motherboard which has the VIA VT8233A South
Bridge Chipset. 
2. Install Red Hat Linux Enterprise 2.1 ES or AS 
3. Using any currently avaliable 2.4.9-e.XX kernel, run dmesg and/or attempt to
enable udma support for hard drive to confirm this chipset it not supported. 
    

Actual Results:  From Description : 

Currently when trying to turn on UDMA you receive the following error:

hdparm -d 1 /dev/hda
 
/dev/hda:
 setting using_dma to 1 (on)
 HDIO_SET_DMA failed: Operation not permitted
 using_dma    =  0 (off)

and within dmesg it shows that this chipset it unknown to the 2.4.9-e.25 kernel:

VP_IDE: chipset revision 6
VP_IDE: not 100% native mode: will probe irqs later
VP_IDE: Unknown VIA SouthBridge, contact Vojtech Pavlik <vojtech>

Expected Results:  Booting the same system to a custom kernel with my patch
applied I am now able to enable udma using hdparm:

# hdparm -d 1 /dev/hda

/dev/hda:
 setting using_dma to 1 (on)
 using_dma    =  1 (on)

and dmesg shows support for the chipset:

VP_IDE: chipset revision 6
VP_IDE: not 100% native mode: will probe irqs later
ide: Assuming 33MHz PCI bus speed for PIO modes; override with idebus=xx
VP_IDE: VIA vt8233a (rev 00) IDE UDMA133 controller on pci00:11.1


Additional info: