tree 8bcc7f4c47e8041a127a32fa481698252a72b429
parent ebeab049b0932903befaf678980df37e0d7dbe27
author Bernhard Kauer <kauer@os.inf.tu-dresden.de> 1251877745 +0200
committer Anthony Liguori <aliguori@us.ibm.com> 1253672158 -0500

RTC polling mode broken

The RTC emulation does not set the IRQ flags independent of the IRQ enable bits.

The original MC146818A datasheet from 1984 notes:
        "flag bits in Register C [...] are set independent of the
        state of the corresponding enable bits in Register B"
Similar sections can be found in newer documentation e.g. in rtc82885.

Qemu and Bochs set the IRQ flags only if they are enabled,
which breaks drivers polling on them.

The following patch corrects this for the update-ended-flag in Qemu only.
It does not fix the handling of the other flags.

Signed-off-by: Bernhard Kauer <kauer@tudos.org>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>