Messages in this thread | | | Date | Mon, 06 Aug 2007 11:04:30 +0100 | From | David Vrabel <> | Subject | Re: sdio: set the functions' block size |
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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
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