[U-Boot] [PATCH v2 2/5] ehci-hcd: Boost transfer speed

Marek Vasut
2012-07-20T13:44:01Z

Dear Beno?t Th?baudeau,

> On Friday 20 July 2012 13:37:37 Stefan Herbrechtsmeier wrote:
> > Am 20.07.2012 13:26, schrieb Beno?t Th?baudeau:
> > > + int xfr_bytes = min(left_length,
> > > + (QT_BUFFER_CNT * 4096 -
> > > + ((uint32_t)buf_ptr & 4095)) &
> > > + ~4095);
> >
> > Why you align the length to 4096?
>
> It's to guarantee that each transfer length is a multiple of the max packet
> length. Otherwise, early short packets are issued, which breaks the
> transfer and results in time-out error messages.

Early short packets ? What do you mean?

> Regards,
> Beno?t

Best regards,
Marek Vasut