[U-Boot] [PATCH 3/4] ehci-hcd.c: Add a new USB_DMA_MINALIGN define for cache alignment

Tom Rini trini at ti.com
Thu Jun 14 21:30:04 CEST 2012


On 06/14/2012 12:29 PM, 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.
>>
>> Cc: Marek Vasut <marex at denx.de>
>> Signed-off-by: Tom Rini <trini at ti.com>
>> ---
>>  drivers/usb/host/ehci-hcd.c |   23 +++++++++++++++++------
>>  1 file changed, 17 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
>> index 04300be..45725f5 100644
>> --- a/drivers/usb/host/ehci-hcd.c
>> +++ b/drivers/usb/host/ehci-hcd.c
>> @@ -29,12 +29,23 @@
>>
>>  #include "ehci.h"
>>
>> -int rootdev;
>> -struct ehci_hccr *hccr;	/* R/O registers, not need for volatile */
>> -volatile struct ehci_hcor *hcor;
>> +/*
>> + * The EHCI spec says that we must align to at least 32 bytes.  However,
>> + * some platforms require larger alignment.
>> + */
>> +#if ARCH_DMA_MINALIGN > 32
>> +#define USB_DMA_MINALIGN	ARCH_DMA_MINALIGN
>> +#else
>> +#define USB_DMA_MINALIGN	32
>> +#endif
> 
> Don't we have some common header for these?

For ECHI and musb?  I did not spot one unless we go all the way up to
common.h or similar.

-- 
Tom


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