lkml.org 
[lkml]   [2007]   [Aug]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: sdio: set the functions' block size
Pierre Ossman wrote:
> On Tue, 31 Jul 2007 16:36:32 +0100
> David Vrabel <david.vrabel@csr.com> wrote:
>
>> Prior to calling the driver's probe(), set the functions' block size
>> to the largest that's supported by both the card and the driver.
>>
>> Signed-off-by: David Vrabel <david.vrabel@csr.com>
>>
>
> Why a maximum size for the driver?

For efficient use of the bus it is useful to pad transfers to a multiple
of the block size. I reckoned it was potentially beneficial for drivers
to use smaller blocks so less padding was required. However, after
looking at some figures the per block overhead (28 clocks for a write)
really does limit the transfer sizes where small block sizes is beneficial.

I'll remove this. Drivers can still override the block size by calling
sdio_set_block_size() directly.

David
--
David Vrabel, Software Engineer, Drivers group Tel: +44 (0)1223 692562
CSR plc, Churchill House, Cambridge Business Park, Cowley Road, CB4 0WZ


.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-08-06 12:55    [from the cache]
©2003-2011 Jasper Spaans