owner-linuxppc-embedded at lists.linuxppc.org wrote: > Benjamin Davis wrote: > >> Errata 9 of >> http://e-www.motorola.com/files/32bit/doc/errata/MPC7455CE.pdf >> talks about some issues with QACK, > > Okay. > >> I further noticed how in arch/ppc/platform/pmac_feature.c, in >> probe_uninorth: if (uninorth_rev < 0x11) { >> actrl = UN_IN(UNI_N_ARB_CTRL) & >> ~UNI_N_ARB_CTRL_QACK_DELAY_MASK; actrl |= ((uninorth_rev < >> 3) ? UNI_N_ARB_CTRL_QACK_DELAY105 : >> UNI_N_ARB_CTRL_QACK_DELAY) << >> UNI_N_ARB_CTRL_QACK_DELAY_SHIFT; >> UN_OUT(UNI_N_ARB_CTRL, actrl); >> >> It would appear to me that a QACK delay is being set by communication >> with the uninorth. I will say now though this is my first >> experiance with the kernel. I was kinda thinking they might have >> gotten around the errata by extending the delay of the QACK. This >> QACK is the system saying it is time to get out of nap, and snoop. > > I don't see any reference in the 64260 manual that lets you control > this. Are you sure that you need to nap/snooze? IOW, are you sure > you're not solving a problem you don't have?
The 64260 does not implement the QACK power management protocol; most boards just tie it off or connect it only to the COP/JTAG header. So, you probably needn't worry about it. -- Gary Milliorn, Motorola phone: 512 996.7066 PowerPC Development Platforms email: mailto:Gary.Milliorn at Motorola.com Computing Platform Division ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
