On Sunday 30 December 2007 16:38, Alan Cox wrote: > > do you have any memories about the outb_p() use of misc_32.c: > > > > pos = (x + cols * y) * 2; /* Update cursor position */ > > outb_p(14, vidport); > > outb_p(0xff & (pos >> 9), vidport+1); > > outb_p(15, vidport); > > outb_p(0xff & (pos >> 1), vidport+1); > > > > was this ever needed? This is so early in the bootup that can we cannot > > None - but we don't care.
Was this embedded outb to 0x80 for delay only? Maybe I'm wrong. But in the case above it forces the chipselect signal to deselect the hardware between the access to vidport and vidport+1. Some devices need this to latch the values correctly. Otherwise the chipselect signal would be active for all four accesses in the example above (and only data and addresses are changing from device's view). Juergen -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
