Messages in this thread | | | Date | Wed, 06 Aug 2008 09:44:26 +0900 | From | Tejun Heo <> | Subject | Re: Kernel Summit request for Discussion of future of ATA (libata) and IDE |
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Robert Hancock wrote: > Here's my first cut at it. Compile tested only. This sets most controllers > to use 32-bit PIO except for those which could potentially be on a real ISA > or other 16-bit bus. It's a bit non-obvious what to do with some of the > drivers, so input is welcome. > > This implementation doesn't check the ata_id_has_dword_io at all, since it > would only make a difference on controllers where we don't really want to > use it anyway. > > It seems like regardless of whether we do 32-bit by default or not the 32-bit > data_xfer function should be added to libata core as we have several drivers > which duplicate the same code currently..
Great, just some minor nitpicks as I don't have much idea about 16 bit ones.
> +unsigned int ata_sff_data_xfer(struct ata_device *dev, unsigned char *buf, > + unsigned int buflen, int rw) > +{ > + struct ata_port *ap = dev->link->ap; > + void __iomem *data_addr = ap->ioaddr.data_addr; > + unsigned int words = buflen >> 2;
dwords maybe?
> + unsigned int slop = buflen & 3; > + > + /* Transfer multiple of 4 bytes */ > + if (rw == READ) > + ioread32_rep(data_addr, buf, words); > + else > + iowrite32_rep(data_addr, buf, words); > + > + /* Transfer trailing 1 byte, if any. */
1byte?
Thanks.
-- tejun
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