[U-Boot] [PATCH v2 12/17] usb: Add support for txfifo threshold

[Stephen Warren]

Simon Glass wrote at Monday, December 05, 2011 7:03 PM:
> On Mon, Dec 5, 2011 at 3:32 PM, Stephen Warren <swarren at nvidia.com> wrote:
> > On 12/02/2011 07:11 PM, Simon Glass wrote:
> >> CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the txfilltuning
> >> field in the EHCI controller on reset.
> >
> >> diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
> >> index 3d0ad0c..cc00ce4 100644
> >> --- a/drivers/usb/host/ehci.h
> >> +++ b/drivers/usb/host/ehci.h
> >> @@ -80,7 +80,11 @@ struct ehci_hcor {
> >>       uint32_t or_ctrldssegment;
> >>       uint32_t or_periodiclistbase;
> >>       uint32_t or_asynclistaddr;
> >> -     uint32_t _reserved_[9];
> >> +     uint32_t _reserved_0_;
> >
> > Why not remove _reserved_0_ ...
> >
> >> +     uint32_t or_burstsize;
> >> +     uint32_t or_txfilltuning;
> >> +#define TXFIFO_THRESH(p)             ((p & 0x3f) << 16)
> >> +     uint32_t _reserved_1_[6];
> >
> > ... and make _reserved_1_ 1 element bigger and keep it named _reserved_?
> > The result would be a little simpler.
> 
> Sorry I'm a bit stuck with that one. I have:
> 
> 	uint32_t or_asynclistaddr;
> 	uint32_t _reserved_0_;
> 	uint32_t or_burstsize;
> 	uint32_t or_txfilltuning;
> 	uint32_t _reserved_1_[6];
> 	uint32_t or_configflag;
> 
> How can I remove _reserved_0_? I would need to replace it with
> something, as need or_burstsize to stay where it is. Can you please
> explain a little more?

Oh right, this is a HW structure, so the layout is fixed? In which case
the patch is fine. I wonder why all the fields weren't just defined from
the start rather than being marked "reserved" though; perhaps it'd be
best to update the code to completely flesh out the HW description at
some point. Not necessarily in this patch though.

-- 
nvpublic