[U-Boot] [PATCH v4 1/1] tegra: usb: Fix device enumeration problem of USB1

[Marek Vasut <marek.vasut@gmail.com>]

Dear Jim Lin,

> >From: Marek Vasut [mailto:marek.vasut at gmail.com]
> >Sent: Thursday, June 21, 2012 6:16 PM
> >
> >> --- a/drivers/usb/host/ehci-tegra.c
> >> +++ b/drivers/usb/host/ehci-tegra.c
> >> @@ -1,5 +1,5 @@
> >> 
> >>  /*
> >> 
> >> - * Copyright (c) 2009 NVIDIA Corporation
> >> + * Copyright (c) 2009-2012 NVIDIA Corporation
> >> 
> >>   *
> >>   * See file CREDITS for list of people who contributed to this
> >>   * project.
> >> 
> >> @@ -29,6 +29,22 @@
> >> 
> >>  #include <asm/errno.h>
> >>  #include <asm/arch/usb.h>
> >> 
> >> +/*
> >> + * A known hardware issue where Connect Status Change bit of PORTSC
> >> register + * of USB1 controller will be set after Port Reset.
> >> + * We have to clear it in order for later device enumeration to
> >> proceed. + * This ehci_powerup_fixup overrides the weak function
> >> ehci_powerup_fixup + * in "ehci-hcd.c".
> >> + */
> >> +void ehci_powerup_fixup(uint32_t *status_reg, uint32_t *reg)
> >
> >So it was even enough to use the already preinstalled callback? :-)
> 
> Yes.
> 
> >> +{
> >> +	mdelay(50);
> >> +	if (((u32) status_reg & 0xFFFFC000) != TEGRA_USB1_BASE)
> >
> >What's this magic number here?
> 
> Address Mask value, any suggestion?

I wonder ... either comment or #define it somewhere, the later is favorable.

> 
> >> +		return;
> > 
> > +	/* For EHCI_PS_CSC to be cleared in ehci_hcd.c */
> > 
> >> +	if (ehci_readl(status_reg) & EHCI_PS_CSC)
> >> +		*reg |= EHCI_PS_CSC;
> >
> >writel()
> 
> The real IO write (ehci_writel) is done in ehci-hcd.c after calling of
> ehci_powerup_fixup. Any suggestion?

Good, leave it at that.

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^^ The above is nvidia bullshit, please remove it, it doesn't make sense here.

Best regards,
Marek Vasut