From: Marek Vasut <marex@denx.de>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH 2/2] ehci-hcd.c, musb_core, usb.h: Add USB_DMA_MINALIGN define for cache alignment
Date: Sun, 8 Jul 2012 23:36:32 +0200 [thread overview]
Message-ID: <201207082336.33152.marex@denx.de> (raw)
In-Reply-To: <CA+M6bXmEQveFj8cqQT_1cJweLrbPjRyYqbHqrrZzu_-kdVm3QQ@mail.gmail.com>
Dear Tom Rini,
> On Sun, Jul 8, 2012 at 11:51 AM, Marek Vasut <marex@denx.de> wrote:
> > Dear Ilya Yanok,
> >
> >> Hi Marek,
> >>
> >> On Sun, Jul 8, 2012 at 7:08 AM, Marek Vasut <marex@denx.de> wrote:
> >>
> >> [...]
> >>
> >> diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
> >>
> >> > index 04300be..5199560 100644
> >> > --- a/drivers/usb/host/ehci-hcd.c
> >> > +++ b/drivers/usb/host/ehci-hcd.c
> >> > @@ -34,7 +34,10 @@ struct ehci_hccr *hccr; /* R/O registers, not
> >> > need for volatile */
> >> >
> >> > volatile struct ehci_hcor *hcor;
> >> >
> >> > static uint16_t portreset;
> >> >
> >> > -static struct QH qh_list __attribute__((aligned(32)));
> >> > +DEFINE_CACHE_ALIGN_BUFFER(struct QH, qh_list, 1);
> >>
> >> This will align on ARCH_DMA_MINALIGN, not USB_DMA_MINALIGN. In case of
> >> ARCH_DMA_MINALIGN < 32 we will loose the 32-byte alignment required by
> >> USB spec.
> >
> > That's true -- maybe we should create ALLOC_ALIGN_BUFFER() and
> > ALLOC_CACHE_ALIGN_BUFFER() to be a special case of it ?
>
> Lets think. USB says "32byte min". Do we have other buses today that
> apply similar constraints? If so, we should probably go about
> abstracting into a __ALIGN_FOO(size, what) and do a general one and a
> USB one that does 32 or cachline. If it's just USB that might be
> overkill however...
Let's do this, we dunno what craziness can befall us in the future. And having
the macro handy won't hurt anyway.
Best regards,
Marek Vasut
next prev parent reply other threads:[~2012-07-08 21:36 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-08 3:08 [U-Boot] [PATCH 1/2] common.h: Introduce DEFINE_CACHE_ALIGN_BUFFER Marek Vasut
2012-07-08 3:08 ` [U-Boot] [PATCH 2/2] ehci-hcd.c, musb_core, usb.h: Add USB_DMA_MINALIGN define for cache alignment Marek Vasut
2012-07-08 10:04 ` Ilya Yanok
2012-07-08 18:51 ` Marek Vasut
2012-07-08 20:52 ` Tom Rini
2012-07-08 21:36 ` Marek Vasut [this message]
2012-07-09 18:37 ` Ilya Yanok
2012-07-10 1:55 ` Marek Vasut
2012-07-14 22:11 ` Ilya Yanok
2012-07-14 22:08 ` Ilya Yanok
2012-07-15 8:07 ` Marek Vasut
2012-07-15 8:55 ` Ilya Yanok
2012-07-15 9:42 ` Marek Vasut
2012-07-08 12:23 ` [U-Boot] [PATCH 1/2] common.h: Introduce DEFINE_CACHE_ALIGN_BUFFER Ilya Yanok
2012-07-08 18:55 ` Marek Vasut
2012-07-20 4:01 ` Mike Frysinger
2012-07-20 11:31 ` Marek Vasut
2012-07-20 21:47 ` Mike Frysinger
2012-07-20 21:50 ` Tom Rini
2012-07-21 17:22 ` Mike Frysinger
2012-07-23 15:24 ` Tom Rini
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