Re: libata pata_pdc2027x success on sparc64

[Mikael Pettersson <mikpe@csd.uu.se>]

Sergei Shtylyov writes:
 > Hello.
 > 
 > Mikael Pettersson wrote:
 > 
 > >  > The libata version has three improvements compared to the IDE version.
 > >  > 
 > >  > 1. The PLL calibration patches in the above URLs (for IDE)
 > >  > still need more improvement as done in the pdc_read_counter()
 > >  > of the libata version.
 > >  > 
 > >  > 2. The Promise 2027x adapters check the "set features - xfer mode"
 > >  >    and set the timing register automatically. However, the automatically
 > >  >    set values are not correct under 133MHz. Libata has a hook
 > >  >    pdc2027x_post_set_mode() to set the values back by software.
 > >  > 
 > >  > 3. ATAPI DMA is supported (please see pdc2027x_check_atapi_dma()).
 > >  >    Maybe we also need to add this to the IDE version.
 > 
 > > Do you know how large the difference is between the 20267 (old driver)
 > > and the 20269 (new driver) in the areas touched by these patches?
 > 
 >     Immense. They belong to the different families, register compatibe only in 
 > the standard PCI/BM IDE regisrer set -- hence was the driver split.
 > 
 > > Long ago I tried a 20267 PCI card in my PowerMac, and it had the same
 > > issues that the 20269 card had. So I'm interested in porting the
 > > calibration/timing fixes to pdc202xx_old.c.
 > 
 >     They don't apply to this driver at all.  The "older" chip family didn't 
 > have the PLL to calibrate.  It must be some different issue.

OK, in that case let's forget about the 20267. It's not _that_ important :-)