Re: [PATCH v2 05/12] tpm: Use read/write_bytes for drivers without more specialized methods

[Jason Gunthorpe <jgunthorpe-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>]

On Thu, Apr 14, 2016 at 11:46:33PM +0200, Christophe Ricard wrote:
> 
> 
> On 13/04/2016 22:42, Jason Gunthorpe wrote:
> >On Wed, Apr 13, 2016 at 09:55:44PM +0200, Christophe Ricard wrote:
> >>Some drivers might choose to implement only functions for transferring an
> >>arbitrary number of bytes, without special handling of word or dword
> >>transfers.
> >Hurm, better to provide common write/read16/32 helpers that a driver can
> >just dump into it's function pointers rather than using null,
> >simpler/faster.
> It is not really clear to me here. In short, Do you expect me to drop this
> patch and force drivers to
> implement their own write/read16/32 helpers so that it will avoid a null
> check ?

No, just do something like

static const tpm_..ops spi_phy_ops = {
   .read_bytes = spi_read_bytes,
   .read16 = tpm_tis_common_read16,
   .read32 = tpm_tis_common_read32,
}

And have the core provide implementations of tpm_tis_common_readXX
that call read_bytes.

Jason

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