Date: Tue, 8 Aug 2006 13:42:51 -0400 From: John Baldwin <jhb@freebsd.org> To: John-Mark Gurney <gurney_j@resnet.uoregon.edu> Cc: freebsd-hackers@freebsd.org Subject: Re: jkh weird problem (reading pci device memory) Message-ID: <200608081342.51800.jhb@freebsd.org> In-Reply-To: <20060807220550.GF99774@funkthat.com> References: <44D4A5DC.7080403@cytexbg.com> <200608071527.50711.jhb@freebsd.org> <20060807220550.GF99774@funkthat.com>
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On Monday 07 August 2006 18:05, John-Mark Gurney wrote: > John Baldwin wrote this message on Mon, Aug 07, 2006 at 15:27 -0400: > > sc->cfg_table.signature = letoh32(bus_read_4(sc->bar.res, 0)); > > sc->cfg_table.version = letoh16(bus_read_2(sc->bar.res, 4)); > > sc->cfg_table.dummy = bus_read_1(sc->bar.res, 5); > > Note that this may or may not be correct... the bus_read_X macros > do endian conversion if the bus is of different endianness than the > processor arch... So if the device is on a PCI bus, and the machine > is sparc64, the bus_read_X will already be swapped as necessary... If > you don't want the byte swapping to be done for you, there are the > _stream versions... The are useful for transfering data like disk > data that needs to maintain the same order... Then why are folks adding these macros to things like mpt? -- John Baldwin
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