> > > Whenever I invoke zgv, I get on the console:
> > > sym53c810a-0: SCSI parity error detected: SCR1=132 DBC=50000000 SBCL=0
> >
> > It may happen that this application access the PCI configuration space of
> > the chip far beyong the pre-defined header area and hits the range that
> > has side effects (IO registers mapped to config space).
> > Such an attack confuses a lot the chip and the driver, btw.
> > If I am right, the only solution is to teach zgv about the PCI specs.;)
>
> zgv just learned :-)
>
> Actually, its svgalib. And it now (in the latest pre-release of 1.4.1)
> reads only the first bytes of each pci device configuration, and reads
> the rest only of vga cards. Hopefully, none of those have this problem
> (which, in my opinion, is stupid, even though it is allowed by the
> specs).
The PCI specs do not require explicitely that the device dependent
configuration space can be read without side effect. All SYMBIOS chips up
to the SYM53C895 have IO registers window (so with read side effects)
mapped at offset 128 of their PCI configuration space -> bad luck. Btw,
these chips donnot conflict with the specs, but may-be such a feature was
not expected by the guys that wrote the PCI specs. :-)
Latest SYM53C896 and SYM53C1010 have no longer IO registers mapped into
the PCI configuration space and so are quite safe for PCI configuration
space read.
Gérard.
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