Thanks for taking the time! On Wed, Sep 6, 2017 at 11:38 Samuel Holland <sam...@sholland.org> wrote:
> Hello, > > On 08/31/17 22:45, Andrew A. wrote: > > I tried the following to no avail: > > setpci -s 00:14.0 0xd4.L=0x00000000 > > setpci -s 00:14.0 0xdc.L=0x00000000 > > > > This seems not to have taken hold upon readback: > > setpci -s 00:14.0 0xd4.L > > 00003fff > > setpci -s 00:14.0 0xdc.L > > 0000003f > > This is also what I get on my machine. > > > (And indeed, the same problem persists -- qemu changes the port > > mappings as soon as I boot a guest, locking me out of my host machine > > until I ssh in and run 'setpci .. d0' again) > > > > I took a look at what I believe is the R/WL property for these > > settings, which is bit 31 of D20:F0:40h according to the datasheet, > > so: > > setpci -s 00:14.0 0x40.L > > 803609fd > > sudo setpci -s 00:14.0 0x40.L=0x003609fd > > Note that the ACCTRL bit is not documented in that register, further > suggesting that it is a BIOS-only control bit. Likely it is a write-once > bit, so once it has been set, it cannot be unset. > > > But this again didn't seem to have an effect: > > setpci -s 00:14.0 0x40.L > > 803609fd > > Note that other bits in the register can be changed (e.g. you can change > the 6 to a 0 to turn off power management, and change it back to a 6). > Just the top bit is write-protected. > > >> Another potential problem is that your BIOS on the host may > >> write-protect the mask register. In that case, see the datasheet > >> for how to unlock it, if possible. > > > > Right, and despite trying to remove the write protect I'm inclined > > to think my unlocking commands are not working for some reason. Do > > you see anything wrong with what I've tried here? > > No, other than that it doesn't work :) I guess we're just out of luck > then, without doing something like patching your BIOS (so the bit never > gets set). > > > Thanks. > > Regards, > Samuel >
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