On Sun, Oct 21, 2001, Georg Acher <[EMAIL PROTECTED]> wrote:
> On Sun, Oct 21, 2001 at 10:26:26PM +1000, Brad Hards wrote:
> > I recently found a set of PIIX chipset errata -
> > http://www2.lm-sensors.nu/~lm78/pdfs/PIIX4-addendum.pdf. I note the following
> > USB related issues.
> >
> > 4. USB Bandwidth Reclamation Errata
>
> > This seems to be required, but (AFAICT) is not being applied in either
> > driver.
>
> Yes, it is definitely. Otherwise the HC would be immediately dead when using
> reclamation. The workaround (QH and TD) is in usb-uhci in init_skel (qh at
> chain_end).
Same with uhci.c. Around line 2784:
/* This dummy TD is to work around a bug in Intel PIIX controllers */
uhci_fill_td(uhci->skel_term_td, 0, (UHCI_NULL_DATA_SIZE << 21) | (0x7f << 8)
| USB_PID_IN, 0);
uhci->skel_term_td->link = uhci->skel_term_td->dma_handle;
uhci->skel_term_qh->link = UHCI_PTR_TERM;
uhci->skel_term_qh->element = uhci->skel_term_td->dma_handle;
and in uhci_inc_fsbr:
uhci->skel_term_qh->link =
uhci->skel_hs_control_qh->dma_handle | UHCI_PTR_QH;
JE
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