On 03/21/2013 03:48 PM, Roger Quadros wrote: > If the bootloader doesn't configure USB DPLL (e.g. in u-boot, > disable CONFIG_USB_EHCI_OMAP), then we get all sorts of problems > like > - division by zero errors at boot [1] > - USB DPLL fails to enter locked state > - USB EHCI Host is non functional > - Device can't enter OFF mode > > Initializing the USB DPLL fixes all these issues. > > [1] > > [ 0.000000] clock: dpll_usb_ck failed transition to 'locked' > [ 0.000000] Division by zero in kernel. > [ 0.000000] [<c001b00c>] (unwind_backtrace+0x0/0xf0) from [<c02b2378>] (Ldiv0+0x8/0x10) > [ 0.000000] [<c02b2378>] (Ldiv0+0x8/0x10) from [<c041cf3c>] (clk_divider_set_rate+0x10/0x124) > [ 0.000000] [<c041cf3c>] (clk_divider_set_rate+0x10/0x124) from [<c041bfc4>] (clk_change_rate+0x3c/0xb4) > [ 0.000000] [<c041bfc4>] (clk_change_rate+0x3c/0xb4) from [<c041c028>] (clk_change_rate+0xa0/0xb4) > > Signed-off-by: Roger Quadros <rogerq@xxxxxx> > --- > arch/arm/mach-omap2/cclock44xx_data.c | 19 +++++++++++++++++++ > 1 files changed, 19 insertions(+), 0 deletions(-) > > diff --git a/arch/arm/mach-omap2/cclock44xx_data.c b/arch/arm/mach-omap2/cclock44xx_data.c > index bfc46c1..6127bb9 100644 > --- a/arch/arm/mach-omap2/cclock44xx_data.c > +++ b/arch/arm/mach-omap2/cclock44xx_data.c > @@ -53,6 +53,12 @@ > */ > #define OMAP4_DPLL_ABE_DEFFREQ 98304000 > > +/* > + * OMAP4450 TRM Rev X, section "3.6.3.9.5 DPLL_USB Preferred Settings" 4460 actually. cheers, -roger -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
