Re: ALCHEMY: AU1200 USB Host Controller (OHCI/EHCI)

[Matej Kupljen <matej.kupljen@ultra.si>]

Hi

(After some confusion about kernel version, I think I found the
problem, sorry about that).

I used binutils 2.15 and 2.16.1, but did not work.

The code in the ehci-hcd.c looks like this:
----------------------------------------------------------------------------
	ehci->periodic_size = DEFAULT_I_TDPS;
	if ((retval = ehci_mem_init(ehci, GFP_KERNEL)) < 0)
		return retval;

	/* controllers may cache some of the periodic schedule ... */
	hcc_params = readl(&ehci->caps->hcc_params);
	if (HCC_ISOC_CACHE(hcc_params)) 	// full frame cache
		ehci->i_thresh = 8;
	else					// N microframes cached
		ehci->i_thresh = 2 + HCC_ISOC_THRES(hcc_params);
----------------------------------------------------------------------------

The problem is *AFTER* the call to ehci_mem_init, where a read from
ehci->caps->hcc_params is attempted, but caps is NULL.

This can be seen by this assembly code form Insight:
----------------------------------------------------------------------------
0x80350758	jal	0x802a3f40 <memset>
0x8035075c	sll	a2,a2,0x2
0x80350760	lw	v1,0(s0)
0x80350764	lw	a2,8(v1)

s0 points to ehci
at offset 0 from ehci is caps
and at offset 8 from caps is hcc_params
----------------------------------------------------------------------------

Where should the caps be initialized?
The only place, where it is set in drivers/usb/ is in
drivers/usb/host/ehci-pci.c:
----------------------------------------------------------------------------
/* called during probe() after chip reset completes */
static int ehci_pci_setup(struct usb_hcd *hcd)
{
        struct ehci_hcd         *ehci = hcd_to_ehci(hcd);
        struct pci_dev          *pdev =
to_pci_dev(hcd->self.controller);
        u32                     temp;
        int                     retval;

        ehci->caps = hcd->regs;
----------------------------------------------------------------------------
But the ehci-pci.c is not included in the compilation, because at the
end of ehci-hcd.c we find:
----------------------------------------------------------------------------
#if defined(CONFIG_SOC_AU1X00)
#include "ehci-au1xxx.c"
#elif defined(CONFIG_PCI)
#include "ehci-pci.c"
#else
#error "missing bus glue for ehci-hcd"
#endif
----------------------------------------------------------------------------

What should be done?
I hope this helps.

BR,
Matej