[U-Boot] [PATCH v3 2/6] ehci-hcd.c, musb_core, usb.h: Add USB_DMA_MINALIGN define for cache alignment

[Tom Rini <trini@ti.com>]

On Wed, Jun 20, 2012 at 09:00:45PM +0200, Marek Vasut wrote:
> Dear Tom Rini,
> 
> > The USB spec says that 32 bytes is the minimum required alignment.
> > However on some platforms we have a larger minimum requirement for cache
> > coherency.  In those cases, use that value rather than the USB spec
> > minimum.  We add a cpp check to <usb.h> to define USB_DMA_MINALIGN and
> > make use of it in ehci-hcd.c and musb_core.h.  We cannot use MAX() here
> > as we are not allowed to have tests inside of align(...).
> > 
> > Cc: Marek Vasut <marex@denx.de>
> > Signed-off-by: Tom Rini <trini@ti.com>
> > 
> > --
> > Changes in v2:
> > - Move test to <usb.h>, expand comment.
> > ---
> >  drivers/usb/host/ehci-hcd.c  |   13 +++++++------
> >  drivers/usb/musb/musb_core.h |    2 +-
> >  include/usb.h                |   10 ++++++++++
> >  3 files changed, 18 insertions(+), 7 deletions(-)
> > 
> > diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
> > index 04300be..5a86117 100644
> > --- a/drivers/usb/host/ehci-hcd.c
> > +++ b/drivers/usb/host/ehci-hcd.c
> > @@ -29,12 +29,13 @@
> > 
> >  #include "ehci.h"
> > 
> > -int rootdev;
> > -struct ehci_hccr *hccr;	/* R/O registers, not need for volatile */
> > -volatile struct ehci_hcor *hcor;
> > +int rootdev __attribute__((aligned(USB_DMA_MINALIGN)));
> > +/* R/O registers, not need for volatile */
> > +struct ehci_hccr *hccr __attribute__((aligned(USB_DMA_MINALIGN)));
> > +volatile struct ehci_hcor *hcor
> > __attribute__((aligned(USB_DMA_MINALIGN)));
> 
> ^ these need to be aligned too?

Yes, these were the first and easy to spot ones in the cache flush
messages, I would swear.

-- 
Tom