Messages in this thread | | | Date | Tue, 05 Aug 2008 20:30:01 -0600 | From | Robert Hancock <> | Subject | Re: Kernel Summit request for Discussion of future of ATA (libata) and IDE |
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Tejun Heo wrote: > 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?
Yeah, those are both leftovers from the 16-bit code. I'll fix them up in the next version, if the approach looks good..
> > Thanks. >
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