Messages in this thread Patch in this message | | | Date | Tue, 18 Mar 2008 02:23:57 +0100 | From | Rene Herman <> | Subject | Re: ehci-hcd affects hda speed |
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On 18-03-08 01:00, David Brownell wrote:
> On Monday 17 March 2008, Rene Herman wrote: >> + case PCI_VENDOR_ID_VIA: >> + if (pdev->device == 0x3104 && pdev->revision >= 0x60) { > > Unless you have specific docs from VIA saying that this register > isn't revision-specific (at least in the sense that all revisions > after 0x60 define that bit in that way), this should probably be a > switch on pdev->revision and just include the known-safe revisions.
I'm looking at a VIA datasheet which says the revision ID for the "VT6212 / VT6212L PCI USB2.0 Controller" is simply 0x60. The VT61212L I myself owned advertised a revision ID of 0x63 and Lev's VT6212L advertises 0x65.
The thing is -- you don't necesarily immediately notice this problem. I noticed it earlier on an old system, as did Lev, but even if on a modern system you may not immediately see an IDE throughput drop, you may still have a sucky system.
With 0x60 documented and 0x63 and 0x65 confirmed as VT6212L, I'd personally still go with >= 0x60 and assume either backwards-compatibility or a "don't care" definition if some later revision were to not define this hack.
> At one point I had a table mapping those revision codes to > specific VIA chips. Too bad I didn't keep it. ISTR that the > VT6212 has a newer revision code than the vt8235 southbridge, > and probably not as new as the vt8237 one...
Some googling seems to indicate that:
VT6202 = 0x5x (0x50, 0x51 at least) VT6212 = 0x6x (0x60, 0x61, 0x63, 0x65 at least) VT8235 = 0x82 VT8237 = 0x86 VT*800 = 0x90 (KM800Pro, VN800, K8N800, ...)
Do you want one with 0x6x? I feel it's very likely that everyone on anything later will then still have a sucky system. Tons of people with VT8235/VT8237 around (although not me). Any quick test available for them?
> But otherwise, yes -- that's the kind of patch I'd sign off on > after making this comment a bit more informative about how > that 1 usec sleep time creates an amount of PCI bus hogging.
Version with 0x6x and the somewhat more expansive comment. I'd like to be able to test VT8235/VT8237 first though...
Still totally untested ofcourse.
Rene commit fd96c2b26339f21a66504cb3f36579bb312a8f3b Author: Rene Herman <rene.herman@gmail.com> Date: Tue Mar 18 00:02:16 2008 +0100
USB: VIA VT6212(L) 10us EHCI sleep time select.
The VIA VT6212(L) uses a 1us EHCI sleep time by default which hogs the bus bad. Use the 10us EHCI spec value instead as suggested by Lev A. Melnikovsky.
CC: Lev A. Melnikovsky <melnikovsky@mail.ru> Signed-off-by: Rene Herman <rene.herman@gmail.com>
diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c index 3ba0166..bdc8af9 100644 --- a/drivers/usb/host/ehci-pci.c +++ b/drivers/usb/host/ehci-pci.c @@ -152,6 +152,20 @@ static int ehci_pci_setup(struct usb_hcd *hcd) break; } break; + case PCI_VENDOR_ID_VIA: + if (pdev->device == 0x3104 && (pdev->revision & 0xf0) == 0x60) { + u8 tmp; + /* + * The VT6212 defaults to a 1us EHCI sleep time which + * hogs the bus badly. Setting bit 5 of 0x4B sets the + * sleep time to the EHCI standard 10us. + */ + pci_read_config_byte(pdev, 0x4b, &tmp); + if (tmp & 0x20) + break; + pci_write_config_byte(pdev, 0x4b, tmp | 0x20); + } + break; } ehci_reset(ehci); | |